I don't think anyone is in any doubt that the low-cost airlines have forced the established carriers to lower their prices to match. I do thank Easyjet, Ryanair and those that came before for that. But the simple fact is that if BA is offering a product significantly better than that of Easyjet for a similar price then I will use it. I don't consider either Heathrow or Gatwick to be "hell" - or, at least, no more so than Luton or Stansted. Getting to them is certainly a lot easier (and, in the case of Heathrow, cheaper). If you've checked in online and are carrying only cabin baggage then almost every airport is a breeze.
I don't know anyone personally who's been left stranded by Ryanair (although maybe that's because I don't know anyone who flies regularly with them). But it does happen - just look at the Skytrax forum - and the mere possibility of it happening puts me off using them, no matter how cheap they are. The measure of a good airline is how they handle matters when things go wrong.