No no, it did not bother me, and I had been extensively briefed on the differences and issues with Franco and beyond. My fiancée was a supporter of Catalan Independence. BUT, as I met her family, they were kind enough to speak Spanish in my presence so that I could understand better. I had briefly studied a phrasebook of Catalan to get down the standard pleasantries, but I figured I would get by in Spanish easily enough.
I believe that mostly, the prejudice was from me being American, or accompanying a beautiful native woman. I also got dirty looks because of the prepaid debit card I was using for everything.
The rude waiter was in a little restaurant in Manresa, and not in Barcelona proper. So, definitely off the beaten path of tourism.
And as far as returning, I would definitely love to; I loved the Sagrada Família and other such shrines; the scenery was gorgeous, and I was struck by how much older it all was in comparison to American structures and institutions. Yet, it was high technology (I had always had this mistaken belief that Europe was behind the U.S. in computers and electronics) and I amazed my fiancée by photographing the back of the TV, the circuit breaker box, things like that.
I would definitely return to Europe, but outside the influence of my ex-fiancée, I am unlikely to return to Catalonia; I'd love to see Italy, the Holy Land, more of England, but especially Ireland. It's all on my "bucket list"!
Sagrada familia ,is modern in every way. In fact almost the entire city is. They choose to build different, but Barcelona had a tiny population and size in 1900.
A factoid that was once uncited in Wikipedia claims that the main buildings in Manresa are all built from rubble, the reason being that Napoleon and his troops demolished and burned the city as they retreated, and so it was literally rebuilt in place from the remnants. I could definitely see that was a plausible story, too.
In the Southwestern United States, we don't have any buildings that were built, let alone demolished, in the early 19th century.
Most of Barcelona dates from long after Napoleon. There are some really old buildings, but the city exploded after 1900. Most of what tourists go to see is Gaudi who worked after that.
Catalan independence is a bit of a ongoing issue there, and some rural areas might frown upon spanish (mexican or not), or whatever!
Hope it didn't make you don't want to comeback