Categorically false. Operation Barbarossa failed for a myriad of reasons, but Soviet preparation should not be counted among them. The Soviets did not believe the Germans would violate the non-aggression pact with such rapidity, and while I have no sources to hand, you can read that many expected war with Nazi German in the year 1946, not 1941.

In fact, many reputable authors agree on the narrative that Stalin was caught so off-guard that he suffered a mental breakdown, as Zimmerman suggests there. Whether he did suffer one or not, the facts are clear: Stalin, and by extension, the Soviet government at large, were not prepared for such an early invasion.

Stalin, on hearing the news, apparently sank into his chair and said nothing (Beevor, p. 9)

The general population deeper within Russia did not know something was amiss, its telling that when the Soviet Government decided it was time to let the people know, that it was not Stalin who addressed them, but rather Molotov:

...at midday, on 22 June [the day Operation Barbarossa began] Molotov's voice, not Stalin's, emerged from the wireless. 'Today at four o'clock in the morning, German troops attacked our country...' (Beevor, p.10)

This is not to suggest that the Germans achieved complete surprise, and Stalin must be blamed for the effect the German assault had; the Soviet embassy in Berlin had sent back evidence, including a phrasebook issued to Soldiers, that suggested impending German military action. Further, the noticeable, if not as complete of a picture of a build-up on the Soviet border should've galvanized some added security efforts.

However, even if the Soviets had managed to take the necessary precautionary measures, the breathtaking rate of German advance probably would've been as disastrous, if not more so. Ironically, by not having the total strength of the RKKA within striking distance of the border, the Soviets probably avoided complete and total disaster, and the Germans main goal - of destroying the Red Army in a rush to Moscow, eluded them as a result. The Soviets deployed many formations to the west, but they were not offensive in nature, and were not even within contact with the operational reserves. As a result, many border hugging formations were encircled and destroyed by the speed, "surprise" and violence of the initial assault.Finally, and as I've mentioned in many responses, the Soviet army of 1941 was not the one that was at the forefront in the world in terms of doctrine and officer professionalism. The Purges of the 1930s had left many a rotten structure in the chain of command, and the German's crushing initial victories are stern evidence of this. Bottom line: In almost every aspect, the Soviets were unprepared for war with Germany.

Sources:

"Stalingrad" Beevor, Antony. London, 1998.

"Soviet Military Operational Art: In Pursuit of Deep Battle" Glantz, David M. Fort Leavenworth, 1991.

"Operation Barbossa: the German Invasion of Soviet Russia" Botley, Oxford. Osprey Publishing, 2013.

"Stalin's Claws: from the purges to the Winter War: Red Army Operations before Barbarossa, 1937-41" Hooton, E.R, Tattered Flag Press, 2013.

Hm, the common narrative of the Soviet offensive hypothesis as I know it says precisely the contrary, that one of the reasons the Red Army suffered such horrendous losses and total disorganization during the first months of Barbarossa was because they were deployed in offensive formations far to the west where they were easily encircled; planes and ammunition were stored en masse and in the open so the Luftwaffe could bomb them to pieces very quickly (the exemplary version of this argument being of course Suwurows 'Icebreaker'). I'm curious to where you heard or read this argument!