IN my view, carpaccio is thinly sliced beef, nothing else. But now, it seem OK to serve salmon carpaccio, or even, as I recently saw, pumpkin carpaccio. Am I to assume that everything thinly sliced and spreaded on a plate can be called a carpaccio nowadays? Can I expect, say, cheese cake carpaccio soon? Or is that still very liberal pretentious use of the name of a specific dish?
"Pumpkin carpaccio" sounds reasonable to me. It's fairly clear what it means: something like carpaccio, but made with pumpkin.
I think as long as people generally understand what's meant by the term, there's not really much point in trying to deem it "correct" or "incorrect". Sure, carpaccio is a fancy foreign food, so this might sound fancy or even pretentious depending on context, but it's still a reasonable thing to say. (And this isn't a new usage; for example here's a melon carpaccio from 2003.)
Of course, this doesn't change what the canonical carpaccio is; that's still going to be meat or fish. But it's fairly typical to combine multiple terms to describe something, even if one of the terms individually definitely wouldn't suggest the right thing.
For example, I'm sure you wouldn't blink an eye at use of the term "tofu hot dogs", even though "hot dog" on its own clearly means meat. The combination of the terms doesn't mean "hot dogs can be made of whatever you want", it means "this thing is like a hot dog, but made with tofu." And if someone tries to say "technically, that's not a hot dog" people will most likely just roll their eyes.
Perhaps some of the issue here is that carpaccio is a foreign word in English, and in Italian the usage is likely a lot more restricted. But in English, people are going to say what it makes sense to them to say, and combining terms like this generally makes sense. (That said, even Italians may be flexible; for example here's a zucchini carpaccio, posted in 2003, that's apparently inspired by the version at a restaurant in Rome.)
As a final note, you said carpaccio means just beef to you. Even the Italian Wikipedia page says it includes meat and fish, not just beef. If you're more picky than Italians about the definition of a traditional food, I think you may be taking it a little too far.