Is it because of the gambling, drinking, or what? I don't gamble but I usually have a decent time visiting good restaurants and maybe seeing a show when I go to DEFCON.
The gambling doesn't do much for me, but I'm a drinker and a social smoker. It's hard to put my finger on what's so grating about the Vegas strip, but something about it puts my teeth on edge. It's a really fake and touristy place, and it's not fake and touristy in a pleasant way.
For me it's the incessant marketing of extremely generic entertainment experiences, amidst a backdrop of sexual exploitation. And half of the marketing reeks of bait and switch.
Plus the fact that it works on a plurality of tourists coming through makes it sad.
I leave Vegas with less faith in humanity than I had when I came. It's been a few years though.
Hunter S. Thompson had it right: try to cram as many drugs into your body as possible, seek out the ghosts of America's dead dreams and you may come out with some semblance of spirit intact.
I call it "the Times Square" effect. Every major city has one. Hollywood Boulevard in LA. Fisherman's Wharf in SF. The eponymous Times Square in NY. Etc. I don't know if the Vegas Strip deserves the title for "absolute worse", but it is certainly conceivable.
Okay, so @arthulia and @hueving, is it "good restaurants" or "crappy, over-priced food"? Never been there, but could somewhat imagine either scenario. Actually I could imagine multiple possibilities for each:
"good restaurants": (1) lots of top-tier cooks go there because money and it's cheap because Vegas, or (2) lots of off-strip places with good chefs trying to make it big.
"crappy, overpriced food": (1) Wolfgang Puck etc, or (2) Even off-strip food is bad and expensive because they can't afford water.
Because Vegas is a massive tourist destination where you are guaranteed to have a deep market of people eating out every day of the week, it attracts tons of restaurants so you do need to do a little research. Picking a random one will likely get you overpriced 'meh'.
There are lots of high-end restaurants, because every celebrity chef in America seems to open an outpost there. But if you're familiar with the originals, the Vegas versions tend to be overpriced tourist versions with limited menus. There are some great restaurants to be sure, but it's kind of a dice roll.
We've gone off the strip for sushi, Korean bbq, Thai, and Ethiopian and had good luck; I don't know enough about greater Las Vegas to judge it. But the strip is bad.