Instead of just looking for these phases (which could describe any fad and offer little insight), how about figuring out what makes some different from others?

Some catchphrases actually serve the purpose of describing something in a unique, vivid way. These are worthwhile. Throw someone under the bus, jump the shark, it is what it is, my bad, it's all good. These can, and perhaps should, stick around - if a phrase has value beyond its cleverness, it's a welcome addition to the lexicon.

Then you've got the ones that are used explicitly as jokes, i.e., they are intended to be clever. That's the category for not so much, what happens in x stays in x, adding "not" to the end of a sentence. These wear out their welcome because jokes get stale. There was a time when I stopped saying, "it's kinda hot in here" because I got so sick of some numb nuts immediately warbling "so take off all your clooothes!"

Finally, you've got catchphrases that add nothing. For these, I'd include at the end of the day and most business-speak. These suck and should be killed.

btw, my first exposure to "my bad" was volleyball in the early 90s, that seems a plausible origination to me.

First, your friend is correct that "not so much" goes at least as far back as "Mad About You," because I know for sure that's where I picked it up.

Second, I think it's too late with "Dude." I first heard that in 1990 (used by the first native Californian I ever met) and vowed I would never use it. Now, 18 years later and in my 40s, I say it constantly. I think "Dude" has replaced the "Man" of my childhood and youth, and is here to stay.

Finally, Spackle wrote:

Some catchphrases actually serve the purpose of describing something in a unique, vivid way. These are worthwhile. . . . . [I]f a phrase has value beyond its cleverness, it's a welcome addition to the lexicon. [And then went on to contrast those catchphrases with those that are merely clever and which deserve to be under-bus-thrown.]

That's a "most excellent" point, so to speak.

Oops ... wish one could go back and edit one's posts:

I first heard "Dude" in 1987, and now 21 years later use it constantly.