You might be interested in this older post by u/kieslowskifan, dispelling the common myth that the "Socialism" in "National Socialism" is indicative of a strong left-wing ideology among the Nazis.

Your buddy is more correct than you are.

For one thing, there was no National Socialist party in 1917. The NSDAP (aka the Nazi Party) began life in the postwar period in 1918 as the Deutsche Arbeiterpartei (German Workers' Party) which was a Bavarian offshoot of the far-right Deutsche Vaterlandspartei (German Fatherland Party). The Vaterland was an attempt to create a hothouse political party that acted as an umbrella for the German right by both the German military and the Kaiserreich's right-wing political establishment like the Pan-German League. The platform of the Vaterlands was vociferously militaristic, nationalistic, antisemetic, and anti-Marxist. The German far-right also contained a strong strain of anti-capitalist thought as well. Wartime propaganda against Britain had directed a good deal of bile against the mammonism of the British Empire and portrayed London's position as a center of stock markets and global finance in the most nefarious light. These anti-capitalist discourses did cross-pollinate with antisemitism rather easily as well. Inevitably, the end of the war led to the collapse of the Vaterland's patrons and the German right splintered up considerably and also drew in a number of disaffected demobilized soldiers and German youth too young to see action but radicalized by the war experience on the homefront. The DAP was one of the examples of this as its founder Anton Drexler cut his political teeth in the Vaterland and his marginal party drew in others like Hitler. There were other splinter groups from the crack-up and radicalization of the wartime German right such as the Deutschsozialistische Partei (German Socialist Party/DSP), a party heavily influenced by the mystical Thule Society and antisemtism. But the DAP and DSP were very much at the margins of the immediate postwar German scene. Most of the mainstream right and their voters went to two right-wing parties, the Deutsche Volkspartei (German People's Party/DVP) and the Deutschnationale Volkspartei (German National People's Party/DNVP).

Concurrent to the consolidation, radicalization, and splintering of the German right was a similar process on the German left. The largest political party of the prewar Reichstag was the Sozialdemokratische Partei Deutschlands (Socialist Democratic Party of Germany/ SPD) with about 30% of the parliament's delegates. The SPD was a Marxist-orientated party, but it also represented a larger political trend of some Marxists away from revolution and using the ballot box as a substitute for revolt. The SPD had been outlawed during the Bismarckian Chancellery until 1890 and its electoral success grew despite bans and the fact that the central government was hostile to it. The SPD though had for all of its rhetoric had become somewhat part of the establishment; the SPD voted for war credits in 1914 and its leadership was near unanimous in supporting the war. This support created a rift between the SPD and a number of its constituents as well as mid-level activists and intellectuals in the party as the war dragged on. The Russian Revolution and the ascent of the Bolsheviks exacerbated this rift and the Unabhängige Sozialdemokratische Partei Deutschlands (Independent Socialist Democratic Party of Germany/USPD) formed in response to the perceived support of capitalism and war by the SPD. The USPD was quite active in the various revolts that characterized the collapse of the Kaiserreich in 1918 and there were other elements in the far-left like the Spartakusbund (Spartacus League) that drew members from the USPD and sometimes worked in conjunction with them, but was also at times fought them as well. This split in the German left continued into the Weimar period with the some of USPD merging back into the SPD while others gravitating towards the newly-formed and Moscow-supported Kommunistische Partei Deutschlands (Communist Party of Germany/KPD).

The sea of acronyms above demonstrate the folly of trying to parse out the political platform of German political parties devoid of context and relying upon one component of their titles. The DSP may have used "socialist" in their name, but their platform was decidedly anti-Marxist and nationalistic. Some of the parties' titles were reflective of a particular time and political context; the USDP asserted it was unabhängig because much of its initial platform was that the SPD was part of the wartime establishment that served the interests of capital and the military. Hitler's own renaming of the DAP into the NSDAP in 1920 was likely the attempt to draw in more supporters disaffected by the current postwar chaos and alienated from the mainstream political parties (the actual rationale is still unclear as even the DAP's press organ at the time did not believe the name change to be of much note).

By the same token, context is also key to understanding the political platforms of these parties. "Sozialismus" or "Sozial" did not have a single, unified meaning within German politics. Both the Weimar KPD and SPD parties claimed to be socialists, but they also held the other as ideological heretics. Much of the socialism of the German far-right was rooted in the anti-capitalism of this milieu which saw capitalism as an un-German foreign import that sapped the German Geist of its spirit. The war experience sharpened this anti-capitalist ideology, but it was apparent in the late-Kaiserreich within the German university system as well as in various branches of government like the military and the bureaucracy. The "socialism" of the postwar German right tended to be less about erasing socio-economic distinctions and more about restoring the imagined community of 1914 when the Burgfrieden (civil peace during a time of war) led Germans to renounce political differences and unite in common cause. The left-wing of the NSDAP as exemplified by the SA and the Strasser brothers, was not really "left-wing" in the sense of German politics at the time. Much of their targets within business and industry were against allegedly "un-German" forms of capitalism like department stores or high finance. SA leader Ernst Röhm's socialism was much more about the camaraderie and egalitarianism of the trenches and he saw the militarization of German male society via the SA/Volksarmee as a way to restore this solidarity. Röhm and the Strassers' brand of socialism were far too much for Hitler's much more middle-of-the-road brand of politics (at least middle within the context of the German right) and he muzzled the NSDAP's left-wing at the Bamberg Conference of 1926 by selectively adapting some of their ideas into the 25-point platform and subjecting the wing's leaders to party discipline. Later, Hitler had Röhm and one of the Strassers murdered when he came into power.