Why Learn Spanish in Barcelona?

Barcelona seems to be an extremely popular destination to learn Spanish, although quite why that is I'm not sure.
The reason I say that is that Barcelona is defiantly pro-Catalan but it's even quite difficult to find Catalan classes in the city, while there are dozens of Spanish academies. People come from all over to learn Spanish but then they'll encounter Catalan on the street very often, which must be confusing.