Mao's father was one of the wealthiest farmers in his town (sure, you could say he wasn't petit-bourgeois because China hadn't reached capitalist development, but he was still privileged socioeconomically), Fidel came from a relatively well off family (his father being Spanish and Fidel having studied Law in what probably is the most prominent Cuban university), Che came from an upper-middle class family and was a medical doctor in Argentina in the 50s, Ho Chi Minh's dad was a scholar and a government official, etc.

i'm not saying we should focus on radicalizing petit-bourgeois people (we really shouldn't) but it's clear that some of them can be great comrades and we shouldn't shoo them off simply based off their class status.