It's not entirely clear that that's Putin's intention either. It may well be to install a friendly pro-russian government. In which case the US in Iraq starts to look not-so-different. I don't think either is remotely justifiable.
I’ve heard a lot of people suggesting that Putin won’t try to occupy Ukraine, but instead turn it into a satellite state ala Belarus. Is that any better? Probably not. But I’m not convinced what the US and UK have done in Iraq is any better either.
That's what the US war machine wants peasants to believe (or maybe those dumbasses actually believe it themselves, I wouldn't bet against it).
Russia may take the Russian-speaking parts and annex it... but they are run by very smart people, so they are not going to try to annex a territory which has a large population of native-Ukrainian speakers brainwashed against them... which could lead to long never-ending civil war. Not to mention, Ukraine is literally the poorest country in Europe (gdp/capita), so if they annex it, it will be more of a libility than anything even if they could guarantee some form of peace.
They'll try to recreate what they have in Belarus in Ukraine i.e. get rid of the puppet America has installed and install their own.