I like to think that I blend in more than most tourists - the ones you see in groups of 8 with 2-3 roller bags each fumbling for the keys and trying to make sure they find the right building - but I'm probably biased.
I'm not sure what BCN's solution will be. Tourism is 12-15% of their economy in Catalonia, so it's not a small chunk for a country with 20% unemployment rate. The hotel options aren't great for what you pay for. AirBnB is definitely cheaper (and usually roomier), but it's a difference when you notice that all your neighbors in "old town" are german / british tourists that pop in for a weekend and then leave. Barcelona does have an ordinance that you can only rent rooms for longer than 30 days - so they have people that come around on occasion to check - but I think it's sort of hit & miss enforcement.
I'm not sure I have answers as much as questions - and it's interesting being on the ground zero and seeing this take place.