In the minds of the people at the time Communism was such a great evil and afront to personal freedom, that "propping up dictators and terrorist" was seen as the lesser evil and preferable.

It's perhaps easy to forget now, but during the 30s, 40s, and 50s the face and "leader" of communism was Stalin – not exactly a friendly chap – and things like China's Great Leap Forward left over 20 million dead (mostly due to incompetence, not malice), and let's not forget Cambodia.

Details differ per care of course, but in quite a few cases all of this was done in the name of "freedom and democracy", which was perhaps not entirely unreasonable too. I'm not saying that it was the right thing to do (many other issues like national sovereignty etc. which come in to play), but I do think it's a bit more complex than your comment. I'm not sure if idly sitting by and doing nothing would have been that great of an option either.

There's a reason that communist symbolism and the like is considered taboo in many formerly communist Eastern European countries, somewhat akin to Nazi symbolism.

America had to undergo a great amount of social change too before it came out the winner. With groups like the Black Panthers carrying around Mao's little red book, it seems to me that America had to (was forced to) become more inclusive to build allies and compete with the soviet union.

Dont you talk about black panthers in this manner.