I'm less old, and I'm in a party, but I've also noticed that it's not so hard to get people to turn out for actions and events, but it takes lot more work to get them engaged in the boring shit, like running meetings and keeping notes. That applies to young people as well as old, and I've not run into many older people inside the US with coherent politics that aren't just ghouls. I known a few old communists, and I've sat through my share of trot meetings.

trying to rehabilitate stalin but in the same breath say deng is good and ok but krushchev bad and also Gorbachev bad

I read this as people viewing history with fresh eyes, given the understanding of what happened after. Like I said I've sat through my share of trot meetings, I heard a lot of Stalin being brought up in completely unrelated topics. It's just dogmatism to be obsessing over in-fights from like a hundred years ago, I prefer to just say 70% good, 30% bad and move on. Deng I think gets a lot of credit because China has managed to lift itself up economically through that- without giving fully over their politics to liberals.

Considering Gorbachevs involvement in the dissolution of the USSR, I don't think it's unreasonable that he gets scorn.