sheesh it's one Taco Bell in the entire country- don't worry folks British culture will survive... For crying out loud....
Heh heh, don't quite get the vitriol myself and agree totally, the thing about British culture is, it's been around a long time and it's constantly evolving, that's a GOOD thing, other cultures come to prominence more when people get fed up with one thing, like the trendiness of British food and small producers which is huge at the moment, rare traditional pig breeds and illegal heirloom seed trading.
I've seen lots of American and continental chains come and go, when I was growing up the only chain Hastings had was a McDs, it was a bit of a novelty, Hastings is no worse now it has a KFC as well.
If you don't like it, vote with your feet and don't go, go out and support your local artisan Taco restaurant if you must!

In my opinion Taco Bell will not kill anyone or anything, except possibly me when all that queso clogs my arteries!
There's room in my life for organic local veg boxes, farmers markets and a big greasy taco!