Regarding LCCs vs HCCs
LCCs often enlargen the market pie, benefiting all. There's a book by Lawton which graphically illustrates (literally) 'the Ryanair effect' on the London-Venice market. Instead of stealing market share from the incumbents, they actually managed to boost demand across the board....so perhaps peversely, LCCs can in some instances boost load factors on the HCCs.......although I suspect Easyjet are aiming to grab market share as opposed to creating new demand, focused as they appear to be, on serving the same airports as their higher-cost competitors.