I'm studying the cold war at the moment and one of the major questions is the inevitability of the Cold War and whether communism would always be opposed and feared in the west or whether the cold war began as result of post-WW2 disagreements over the settlement of Germany and other issues.
It certainly seems like the former is the "official" explanation whereas the latter is the practical reality of the situation.
I think certain case studies would affirm that you are correct in thinking that geopolitics was more important than ideology. For example, Tito's Yugoslavia (a communist nation) enjoyed relatively warm relations with the West and chilly relations with the USSR. Similarly, Sino-Soviet relations soured to the point that they had more nukes pointed at each other than the U.S. On the other side, the Soviet Union enjoyed warm relations with non-NATO capitalist countries like Finland.
If a conflict between the U.S. and USSR was inevitable it was due to a competing desire for global influence and hegemony, not because of ideology.