In Barça you need great football as much as great results. In Arsenal nobody cares about the way you win, just do it. I think this is what we have to consider
And maybe more importantly, in Barça you don't have much time to build your project. Half a season, or full season at most. Not 5 fucking seasons and 1 bilion dollars. At least I personally would not settle for it, even if we manage to create a dominant side after. And I believe a lot of others wouldn't either