MUFC - why would Ryanair want to fly Barcelona-Stansted ?
They already fly from Gatwick, Luton and Stansted to Girona 25 times per week and Luton + Stansted to Reus 8 times per week.
Easyjet fly from Gatwick, Luton and Stansted to Barcelona 8 times per *day* !
Not forgetting BA who fly an additional 8 times per day to Heathrow + City
Yes, Barcelona is a nice place, but at some point, the London-Barcelona route must surely reach saturation point.
Comparing the routes from Barcelona El Prat on Easyjet and Ryanair, the only one with any competition is to Milan Malpensa / Bergamo, and if you stretch the interpretation a bit maybe Dortmund / Weeze.