chornedsnorkack: Therefore, low-costs should also be unable to afford driving passengers away.
Indeed. They can't. But in that sector, good service is not the only pull factor - for some of them, service is not a pull factor at all. The low fares' biggest pull factor is exactly that - (perceived) low fares. That's why they work so hard to market that feature of their proposition. If they lose their pax to competitors, it'll be more likely because the price is wrong, not because the frills are absent.