I'm not sure it's as much wising up as it is just burning out and being lost in the shuffle. There aren't many active gang members in their late 30s. By that age life has just happened to most people in some form or another, and aside from rare exceptions, it's very difficult to maintain respect and effectiveness in a game dominated by adolescents.

"...the successful annihilation of organized crime's subculture in America would rock the 'legitimate' world's foundation, which would ultimately force fundamental social changes and redistributions of wealth and power in this country. Meyer Lansky's dream was to bond the two worlds together so that one could not survive without the other." - Dan E. Moldea