I got my first UK airline job because of bush flying. The boss thought that I must be a decent chap as I'd been flying for an NGO in Africa; what a bizarre way to recruit! Unfortunately his maintenance was considerably more African than the African's, and after one maintenance-related accident I quickly left to save my skin and licence.
Having flown since with Capts and FOs of all backgrounds I'd hazard a guess that those who have done something different, and particularly had some variety in their flying careers have a better basis for decision making than the one-type-for-life fella who came to it straight out of flight school. I now regularly fly with these, who are all excellent pilots, but sometimes lack the judgement that comes from broader experience, particularly so as my company seems to actively discourage initiative and thinking (aka airmanship) by stifling them under oppressively detailed SOPs.
If you go straight to jets you've missed out entirely on life between 3000' and FL330, and that's a big hole in your repertoire. As a line Capt my choice of FO is ex turboprop, skipper or FO matters not, and if they've done some bush or utility too then so much the better, they've got the scars and medals to prove it. I'm just not convinced about the "monoculture" career path.