I found this bit of Wiki trivia:
"During filming, Beatty lectured his Russian extras on the capitalist exploitation of labour, attempting to inspire them. According to the magazine Total Film in 2004, this was the 4th "dumbest decision in movie history": the extras duly went on strike, demanding higher wages."
If this story is true, it would seem that Beatty had the typical Hollywood-idealized view of communism, and I would think that Beatty and Keaton were as "smitten" as Reed and Bryant.
Certainly one could see the movie as nothing more than a romance set against the background of the Russian Revolution, but I never saw the film as being particularly critical of the commies. The revolution seemed to be part of the romance. If Beatty worked that long on a movie about Reed it was not to make any sort of anti-communist movie. Reed's quarrels with the Comintern seemed more based on the fact that his branch of communism was not to be the "official" party in America, so his disillusionment seemed to be based more on personal rejection than any cooling of communist ardor. Had he lived, he might have exposed the Russian leaders (Lenin, Trotsky, Stalin) as the brutal murderers they were, but he didn't.
Beatty is a leftist and has been for decades. I just objected to the idea of the film being a ‘Valentine’ to the commnists. Ever see some Stalin era Soviet films? Those are Valentines.