In the case of religion (whether or not I believe it is positive or negative) I know that there are many many dark corners that the "it is all about love" person is not talking about.
Same thing with comunism, I have known in my life people I would be slightly afraid to see holding power flying that banner and we all know what happened many times in history, and while this can be said of many ideology in my opinion the comunism cluster looks like it is trying to sweep the dust under the rug.
I am sure that there are a lot of people that are trying their best to rehabilitate comunism from the curse that Stalin and many many others have cast and I wish them the best of luck, but I do not think that their job is close to being done.