Here's some advice: If you don't like catchphrases, do some research on how to smarten up the rest of society. People seem to have the memories of chimps: They need something loud, annoying, and fast to actually have it stick in their heads long enough to make an impression.
Why else would people STILL be parrotting "Is that your final answer?" Or even as far back as Urkel?
It's annoying, but it's a part of the commercial sale of comedians.
As far as Jeff Foxworthy...Well, people like to laugh at a segment of the population that isn't them. Actually, my girlfriend's family likes Foxworthy, and they ARE rednecks, so there goes that theory...
Actually, there are certain groups that it's still okay to poke fun at...White people primarily. As Redneck and "white trash" are pretty much synonymous in most people's minds, it's okay to pick on them. So since people are being told that these are the only acceptable groups we can really laugh at, people tend to laugh at them all the more (even if they're part of that group), whether or not the jokes are actually all that funny...