I'm fine with using the term "whataboutism" when it is used to expose hypocrisy.
I'm also fine with using the concept of "whataboutism" if one is arguing for a level playing field.
But, when people use the term to silence a defense of Trump, such as "You can't defend Trump doing X on the basis that Obama did X." ...well, that is bogus. If Obama did X and X was ok when he did it, then yes, it is ok for Trump to do it, unless and until the person saying that says they condemn Obama for doing X as well. Below, you tried to use it on me (what about Trump's pork spending, you said, to stop me from criticizing paying for gender studies degrees, something apparently very cherished by you), but I embraced the attack: I would cut all spending, not just the spending I think is moronic. Your attack failed. But, you probably didn't even notice.