We have to separate two distinct things. News media operates two different kinds of content. They have the news, and this is where they actual report the events as they are in professional manner, and they editorials and opinion segments, where they express their slant either themselves or by the guests they bring on. The former is probably what you saw, but if you go look at the latter, MSNBC is most definitely not pro-Trump's military parade.

Here's a few examples:

I served my country. Trump’s military parade was horrifying for a specific reason. It’s not simply because he’s showing off the hardware.

The ‘No Kings’ mass mobilization debunks Trump’s biggest myth

Republicans struggle to defend Trump’s military parade as tanks prepare to roll in D.C.

This is a reflection on the support bases of each party, not the media.

The American left is notorious for purity testing, gatekeeping, and infighting. They will criticize each other and be outright nasty to each other over everything. The more left you move, the more true this is. For whatever reason, the American left deems anything that doesn't 100% align with their views to be either right wing, frauds, or traitors. Because of this, Democratic politicians have to walk around eggshells and try to appear perfect in order to try and appease everybody to secure votes.

The American right doesn't have this issue. They don't give a shit about anything. They don't care if you're senile, a felon, corrupt, unqualified, a grifter, a former Democrat, or full of shit. As long as you tell them Democrats are bad, this country is the best ever and its under attack, and that conservatism can fix it all, they will love you and adopt you no questions asked.

Yes, there is. The big media outlets have been harping about how Trump has been a deranged moron for a decade now. Seriously, what alternate reality do you live in? The media has actually relatively positive of Biden. Them covering his mental decline is an exception, not the rule.