Speaking as a ln anarchist/council communist... There are some good instances and I simply don't see the bad ones if I'm on an instance acc with good defaults.
I don't view it as problematic if people are put off by Lemmy holding more normal, less capitalist and less reactionary views.
That said, in terms of preference, I'll pick free communist groups over tankies and liberals (I decline to ever consider fascists an option at all).
In these dark times I'm not quite sure whether we can afford to lose what allies we have. But we do need to mold what can be sympathetic to our progressive and left-wing causes.
Piefed is problematic for me - although it has a lot of modern features, I oppose the karma system there. I prefer a system that cannot be abused by bots.