I think it is reasonable to point out the hypocrisy. By the numbers, Obama was just as tough on our southern border.
It's not about the numbers, it's all about not being an absolute disgrace while handling the topic.
However, the rule of law was still enforced. Obama concentrated on immigrants with a criminal record and those "picked up" at the border. Family separation was rare, and there was an advocacy and appeal process. USCIS judges were not silenced and neutered. It was far from a perfect system, but there was an attempt to make it compassionate.
This is why the numbers don't tell the whole story. G.W returned more than Obama, Clinton more than G.W., H.W. more than Clinton.
This is not a Obama vs Trump issue - this is a "Every US President in modern history" vs Trump issue. It is possible to enforce immigration laws compassionately. It is not hypocrisy to call this out.
This is why people are crying whataboutism. "Attempts to discredit an opponent's position by charging them with hypocrisy without directly refuting or disproving their argument," per Wikipedia.
Downvoters: I'm curious if you believe my facts are incorrect, or if you're just downvoting because you don't like my politics.
Of course if you engage in this sort of "fallacy fallacy!" argument style, you rapidly get far from the discussion on the actual topic. The best move is probably just not to play.
[0] https://rationalconspiracy.com/2015/03/08/the-chinese-robber...
[1] https://slatestarcodex.com/2015/09/16/cardiologists-and-chin...