It's probably just the disconnect between the two sides of american politics. On the right it's justified enough, on the left it doesn't matter what Trump says, the reaction is going to be exactly the same.

For example I'm not american and mostly on the right, and I think it's doubtful if it's legally justified (how does one legally justify a was anyways? it's extra-judicial almost by definition), but it makes a lot of sense, it aligns with realpolitik and it's morally good for several independent reasons. In particular it has a hugely disproportionate geopolitical impact, and less importantly it can bring a few million people from under a dictatorship.

As an interesting aside, I recently did a quick research on the Grenada invasion, widely spoken of as an embarrassing moment. It went... very well. They came, remove a budding dictatorship right after a coup, left in two months, and Grenada had no ill effects in the years after (both by subjective reporting, and by GDP per capita comparable to neighboring countries). The alternative would have been "do nothing", skip the reputational hit and have yet another hellhole in the region. The number of dictatorships that did well in recent history is exactly two, and neither was socialist (SK and Singapore).