yes it's cheap, yes it's quick... but man, the way they overcook their meat is legitimately disrespectful to livestock around the world. I've never had meat there that wasn't cooked for at least twice as long as it should have been. Truly, if you can't make better tacos at home, you have no idea how to cook.
180 taco has far better tacos. Yes, they are more expensive, and yes, they aren't technically a Mexican restaurant, but they have two or three Mexican taco options (not including specials) that are better than anything you can get at Don Joaquin's. If you go to 180 on Friday, their Al Pastor is the second best taco I've ever eaten, second only to fresh shrimp tacos from a taco shack in Baja California Mexico.
Trust me, don't go to Don Joaquin's it's just another meh Mexican restaurant in Utah county. They get the flavors kind of right but they cook the living crap out of their meat.