It seems that to succeed with a ground-breaking airline, you need a high-profile leader. Which is why Virgin, EasyJet and RyanAir are so well-known and popular. Or rather were, until Stelios left....
Whereas Go and buzz quietly got on with things and were popular with their loyal passengers, they didn't quite have the high profile of airlines run by Stelios or Mo'L. So they no longer exist (unfortunately), whereas the others do.
Leadership. Need one say more?