Visited Barcelona a decade ago to see this. It's awesome. I often think calling it "kitsch" is some sort of unfortunate linguistic quirk because Antonio Gaudi's name evokes "gaudy."
The thing is a celebration of creation, inventiveness, and natural beauty. Maybe even playfulness - though being a catholic building there's some requisite "death" mixed in: I guess the full spectrum of life is lurking in there.
The English word "gaudy" (probably) comes from the Latin gaudere or gaudium (to rejoice, joy), which is also the (supposed) origin of the name Gaudí. Much more appropriate than its current meaning in English.
An element of Gaudi's work I didn't appreciate until I was in Barcelona is the usage of biological structures in his architecture. You can see somewhat in the image looking at the ceiling, but the columns really do evoke the sense of being in a forest of pure white, towering trees with the ceiling as its canopy.
This ties in with the Art Nouveau movement which he was a part of. If you look at paintings and other architecture from the time period, there are lots of references to nature and "organic" shapes.
The thing is a celebration of creation, inventiveness, and natural beauty. Maybe even playfulness - though being a catholic building there's some requisite "death" mixed in: I guess the full spectrum of life is lurking in there.