You peeped that, didja? They know that this impeachment will greatly impact the Republican party for A LONG TIME after. They need to retain their dignity and have Trump finish out with pride otherwise they're going to go out real sad.
They want to set tones.
There is a younger, smarter more polished Trump waiting in the wings to scoop up the cultists. They need to still be in Trump's somewhat good graces to get the co-sign.
The people who helped the mob still want to be around to sell intel and if they get outed and removed from office, they can't do that. I believe it's way more republicans involved in this than those who have been named.
And of course, they need to keep the mob at the ready. They know the mob ain't gonna unify with nobody. They're banking on that. This the final act and they need the cultists to sow terror throughout the country.