Opportunism and fear.

Whether anyone likes it or not, Trump will be the US President for the next four years. For businesses, especially large ones, that means they will need to deal with his shit for the next four years. They can either take a "principled stand", which will likely hurt profit and not gain them anything tangible (read: money); or, they can suck up and try to get in on the grift gravy train which is going to be running out of the White House for the next four years. This has a much better expected value. So, the choice is pretty clear. Businesses are amoral and only care about profit, don't count on them to do anything which runs contrary to that motivation.

For politicians, especially those on the right, the calculus is about the same. Trump has basically been the flag bearer for the right for the last decade and will continue to be the center of the right for the next four years. Where is a GOP politician is going to seek electoral support? No one on the left is voting for a GOP candidate, swing voters are damned near a myth at this point in history; so, that leaves seeking votes from the right. Which brings the politicians right back to Trump. Not sucking up is political suicide for a GOP politician right now. Expect more DeSantis style embracing of Trump and more Susan Collins "I'm voting with Trump, but pretending I won't just long enough to keep my seat in Maine".

Guy has shown himself to grant massive favors for mild compliments and impose massive penalties for mild insults.

It’s rare that you can make a difference of millions of dollars for your company by just saying nice things for an hour, so execs are jumping at the chance.

Money. They think he will (directly or indirectly) influence their ability to make more money.

He has the ability (along with his cohort of cabinet picks, and the supreme Court he stacked) to influence regulation policy in a detrimental way for the public that would be beneficial for the corps. Less/looser regulations = more money they don't have to spend to comply with regulations = more profit.

Power hungry cowards that will snivel at anyone's feet in hopes that someday they can weasel their way into being the king.

Who exactly is "everyone"? I don't really see much of it.

In addition to what’s already been stated, there was much talk on his campaign trail regarding “retribution”. Openly stated and promised. As such, I think people are in survival mode.

Cowardice and greed

They used to have to pretend. Now they don't.

Most people do stuff because they mean it.

Politicians and some others do stuff because they think it will get them power/votes/money/influence etc.

Their behavior is completely inconsistent with respect to having a stance or opinion. Their behavior is completely consistent with respect to trying to be in a favorable position. Once Trump's out, they will turn right around and do or say whatever they think puts them on the winning team, even if it's the complete opposite of what they're doing now.

It's plain as day, yet hard to see because it's so bafflingly spineless.

Because the orange traitor bitch won. Those in the public sphere with something to lose are now hoping he’ll leave them the fuck alone. Fucking cowards.

They do the theater for pedons but they will work with whoever is in the white house and congress, the owner class doesn't care since they win no matter what.