Taco Bell (AKA "taco smell") has been the bottom of the line Mexican fast food franchise here in Los Angeles for decades. It was the "go to" place when you wanted cheap beans and tortillas, and maybe a dead cow run across it a bit.
It makes sense to me for them to reposition their offering and perhaps seduce a higher end market, as opposed to being "we're the cheapest, the bottom most common denominator."
If you want cheap you go to taco smell. If you want better you go to Chipotle or similar. Maybe it's dog eat dog or die. Maybe taco smell realized they're selling the dog equivalent of tacos and burritos. Maybe they aspire to not be the bottom feeder.