Standards of service are not just about 'inflight' service, they encompass all aspects of the paying customer experience whether it be delays or cancellations or the coffee being too cold, or the airline agent in Mumbai unable to understand what they say. The 1.5% you cite ,slim slag may be irrelevant, but the rest isn't. The problem is that too many people like to imply that airlines as a service industry are a special case, where people are only looking for cheap, and that is simply not true.
Invariably in a service industry, clients are looking for value for money, a completely different proposition to 'cheapest price'. The problem is that to some people value for money means the cheapest dirtiest ticket available, to others it means having pleasant staff who treat you with courtesy and respect, whereas to others it means lounge access, meals, comfy seats etc.. All of these different types of groups want their own 'needs' met, but at the cheapest possible price. They all want VALUE FOR MONEY. I do not regard paying 300 quid for a return ticket from Luton to Edinburgh with Easyjet to be value for money, but if it was ten quid, then I would think it was.
That is the problem, ask anyone about flights and they will say they want it cheap, but to each of those people, their service expectations differ. It does not mean they want sh*t service.
As regards budget airline punctuality part of that is due to these airlines flying to less busy airports for much of their network, and not allowing for passengers interlining (i.e point to point only with no baggage transfers). Comparing these figures with the likes of BA/AA is like comparing chalk to cheese.