The CPGB in its final decades attracted a fair number of capable people of one sort or another. Capable people tend to be able to get decent jobs, if that's what they want to do. The question should be: did they get those jobs because of or despite the time they spent in the CPGB? In most cases, I'd say it was mainly despite their party connection. Joining the party was not normally a good career move, although party activity did give members all sorts of 'transferable skills' in organising, campaigning, networking etc. And a party past was more disadvantageous in some areas of work than in others...