Flip-flops and socks

I remember there was a time, long ago, when you could walk around the city center and find more locals than tourists. Now that is almost an almost impossible experience, and it becomes more evident during the touristic peak season...although I am starting to think that Barcelona is always in "high season".
By the way, and for the record, I have nothing against tourism itself, I am only pointing an objective fact.
Well, we have always associated the word tourism with another word, which may be a little unfair, "guiri", a word including some characteristic as blond or red hair, extremely burned skin by sun exposure (known as "prawn effect"), flowered-printed shirts, hanging cameras.... and sandals or flip-flops with socks!