Like most people, I've been to several of the eateries featured on Diners, Drive-Ins and Dives. I recall meeting the owner of one of them (not in Houston) who loudly and profanely cursed host Guy Fieri for selecting his restaurant, then loudly (and profanely) complained about the "new clientele" the show had drawn in. I hadn't gotten my food yet, so I didn't ask a) why he agreed to do the show in the first place, and b) if he was returning the new customers' money.
But this appears to be an uncommon response, judging by the fact the majority of the restaurants featured on the show prominently display links to the show. Like it or not, Fieri is one of Food Network's biggest stars, and a visit from His Goatee-ness can help boost business significantly.