i think everyone has their own thresholds, and their own reminders. ie, i don't think there's anything wrong with engaging in actions that have not caused significant change in the past, as long as we remember that that is the case. we meet interesting people that way, perhaps learn interesting skills, etc.
as far as i'm concerned the issue is thinking that we know what is going to save the world. (it's even possible that thinking we're going to save the world could save the world; i don't know!)
I don't even know what saving the world means!
I don't personally think that reforms are necessarily bad, but I do think they have a tendency towards recuperation, as BA@ implied. Often times it isn't black and white. You are correct - marijuana legalization would lead to lower levels of incarceration - and putting people in prison isn't something I am in favor of ever, so on that level this reform has a benefit. On the other hand, the state I live in has legal marijuana and is now using the sale as a new revenue source for projects which expand state control, including that it is bringing what was once a black market economy under state regulation. I don't smoke weed, so this impacts me in less direct ways than some, and since I don't vote, I played no role in that decision.To be honest, I mostly avoid the sort of reformism you speak of be not engaging in a lot of struggles where that is the outcome, or if I do, (examples, engaging in street protests following cop murders, certain ecological issues), I attempt to bring an analysis that pushes beyond the proposed reforms of the leftists.