Wikipedia:Hand-waving

Hand-waving is a pejorative label for attempting to be seen as effective – in word, reasoning, or deed – while actually doing nothing effective or substantial.

So it's an insult, and quite a common one on talk pages when the discussion heats up. And there are several reasons to avoid it in talk page discussion.

One is simply that it appears nowhere in policies and guidelines. Hand-waving (whatever it means) is nowhere forbidden. A weak argument, but one to consider.

A second is, it's in the eye of the beholder. If there are logical problems with what another is saying, address them. Just describing them as hand-waving isn't very helpful. Exactly what is wrong with the argument?

But thirdly and most important, allegations of hand-waving are often themselves better examples of hand-waving than the argument being criticised. They do not show any understanding of the material, or even any attempt at understanding.

Do a search. I don't want to cite particular examples. Far better you find them for yourself.

And ask yourself, do I seriously want to be numbered in that company?