Look where you live, and look where other people live.
You have easy access to good (and some great) non-chain restaurants (As do I)
Try going to somewhere in the US that is an hour drive from any major city. You are going to find Friendly's, Red Lobster, Outback Steakhouse, Appleby's, and TGI Fridays.
For many people WDW provides easy and ready access to decent dining.
And
For those who don't travel on a regular basis, WDW provides a 'safe' selection. While you may not have a mind blowing meal at a WDW restaurant, you are also not going to have a completely horrid one either. I have been in cities where I have not been able to do any research beforehand and just picked a place blind (I still do that in the Times Square area as restaurants there open a close on a daily basis). Sometimes it is great. Other times I am yacking up bad seafood all over a hotel bathroom.
-dave