You can't look at things that simplistically. The choice was not entirely Stalin or not-Stalin. It was Stalin or Hitler, then later Stalin or McCarthy.

Remember that the threat of Communism forced western capitalsit society to make huge concessions to the workforce. Even the thirties were less brutal, less raw than the recessions of previous eras- purely because the lower orders had an outside force to which they could threaten to transfer their allegiance. Capitalism operated best (for most people under its control) when it had competition- ironic?

As for people knowing about Stalin... people partly knew, but partly didn't want to believe- after all, there WAS black propoganda, our lords and masters haven't always been totally open about the full facts.

I suppose in a way it's like famine relief- if the churches didn't do it today, probably no one would. Because religion gives people the ability to think in black and white, they can motivate themselves to do what they see as totally virtuous, no need to ask questions. The side issued (why does it NEED to be called "Christian" Aid? Are you pushing an updated version of what the Chinese called "Rice Christianity?)

Similarly, a strong belief like Soviet Communism could give people the ability to act unhindered by second thoughts. The welfare state in Western Europe, the NHS, and the whole tenor of European society today makes me glad that they did.