Do you think that people are automata, and any attempt to build a system with X attributes necesarrily also has Y attributes, in the automatic way that eating only sugar leads to diabetes?
Just because there was an attempt to build X (socialism for example), under specific circumstances (e.g less technologically and politically advanced countries such as Russia, Eastern Europe and Asia), under specific forces (20th century colonialism, WWII, cold war etc), and with specific people at the helm influencing things all around (Stalin and Mao basically), doesn't mean any attempt to build X in different circumstance will end up the same.
Putting everything in one communal basket and expecting people to behave is a recipe for disaster. Don't make a system which works only when people do not make mistakes or are only driven by their purest feelings.
[Citation needed]
Because, you know, that's the analogous response to banning all socialism and social-democracy forever just because the Soviet Union didn't turn out well.
tl;dr don't grant it moral credit.
You're taking a look at countries that have implemented 'socialism' and ended up with what amounts to dictatorships. Do you really think that Communism as envisioned by Karl Marx included someone like Stalin, or the corrupt officials that inhabited governments in the Eastern Bloc?
For all of the rhetoric that the far-right sling around in the US about the evils of Socialism, even they have Socialist policies. The government regulates, picks winners, keeps companies afloat that are 'too big to fail,' Social Security and other welfare programs, etc.
Don't confuse situations where neighbors reports other neighbors who then 'disappear' as having anything to do with Communism or Socialism (or than that they have historically resided together).