I think too much is being made of all this - I've never heard anybody say "Jet2? not flying with them, their not sophisticated enough!" or "Jet2? not flying with them cos their planes look too boring/gaudy". Has anybody else?
I have heard people say "Jet2? not flying with them cos I can get the flights cheaper" and "Jet2? not flying with them cos the flights aren't at the right /time or they don't go where I want to go". Might be more productive areas for attention.