I have just moved to Valencia and have been flying here three times a month for the past 2 years and I have never seen a EasyJet or Ryanair flight with many (if any free seats). So I guess Spain’s third largest city is a viable route for them both. With the Grand Prix here for the next few years at least and the Americas Cup coming back it can only get busier for the leisure market and I think BA were a little short sighted in pulling out.
Having to fly via MAD or BCN for miles/points is a pain as I found out a couple of weeks ago when I missed my connection and had an unexpected night in a BCN airport hotel. Sometimes EasyJet prices are massively expensive... in excess of €350 and I would rather spend that with BA to be honest.
Anyway.... that is my two pennies worth. I hope BA start to fly here... I would use them :-)