The problem with communism is the same problem with unregulated capitalism: when you give extraordinary power to a small minority, everyone else suffers. There

The problem with communism is the same problem with unregulated capitalism: when you give extraordinary power to a small minority, everyone else suffers. There's also the problem that violent revolutions are extremely risky, and are unlikely to result in anything but a dictatorship, exacerbating the previous point. Most failed communist communist governments have these problems, as do most failed capitalist governments. Until you have a peaceful transition into a communist system properly hardened against corruption, you'll have little real reason to believe it is any more flawed than capitalist economies.