O-5 isn't that much power - as a battalion commander, that's leading about 300-1,000 soldiers. They wouldn't necessarily be leading troops, but instead be in advisory roles where the rank might have them be taken a little more seriously by flag officers than if they were commissioned as a company grade officer.

Direction commission officers aren't line-officers (AFAIK), so they are don't command in the way you're describing. That assumes doctor/lawyer/nurse though...

Is it about giving them power? Or making them subject to it?

I don't know any tech execs and I am only remotely familiar with the military, but I am hazarding a guess that the cultures in tech and the military are not at all similar. I'm also guessing that there is a massive difference between fighting for Ukraine by using your tech skills and participating in a time-limited, no-real-skin-in-the-game learning exercise.

Not to mention that at the same time this is happening, SecDef fired a number of generals, and the military is being used for political purposes, at least according to some.

Everything you said is true. But regarding your last point, I mean, the military has always been used for political purposes.

"Politics by other means" and all that, but the US military being overtly used for partisan politics was not the norm for the US.

Why?

Bad for whom?