I like the show because it's meant to be intentionally slow paced, conventional, satirical, and mundane kind of comedy, and not a bunch of rapid one-liners, flashbacks, cultural references or sexual jokes throughout. It's always been that way. If you were a fan early on, you appreciate the show now, but if you've only tried watching within the last 5 years, you'll probably not like it.
Sure, it's not in my top 5 or maybe top 10 favorite TV shows, but I would never ever call it garbage. True "garbage" doesn't stay on the air for 13 seasons. There's no way around that, I'm afraid.
Maybe the attitude and expectations of the typical cartoon watcher has changed from a decade ago, I dunno. I mean, look at South Park now and compare it to ten years ago. Look at the Simpsons and look at all of the long running TV series in general. The writers and the producers of these shows have all made changes and adapted quite significantly over the years.
I suppose King of the Hill is one of the few shows that hasn't changed as much and now people aren't into it anymore.
-TNC