I am curious what restaurants you ate at? There are dozens of great restaurants right downtown that have very good, homemade and high quality food. There are the places that cater to the tourist crowd, but they are usually easy to spot and from what I have heard, actually have decent food (albeit not local or Mexican food). Then there are the cruise ship piers, with Hooters, Senor Frogs, Hardees, Starbucks, etc. Take those for what they are worth- the same junk you can get anywhere!
I stayed at Blue Angel last week and found the food there to be very, very good, and I enjoy the ease of quick breakfast and lunch, especially on 4x dive days. The service was spot on as well.