it can be wrong but It's strange or not only depending on your assumption of Russia end game here.
To me it's annexing/establishing proxies in east part of Ukraine and forcing naturality as secondary goal. I Don't think Russia has real interest in actually occupying western Ukraine.
Dealing of Russia with eastern Ukraine could have played out like the war for Crimea and Donbass, a limited conflict with less intensive fighting and less deaths. those conflict had a few thousand deaths over 10 years opposed to the tens of thousands already and that number will only get worse.
NATO didn't make them do anything, Russia asked for considerations and guarantees on Ukraine status and they were ignored for a decade. Now from Russian perspective they have the casus Belli to forcibly submit the whole country into "naturality" instead of just occupying some of the territories they want. This gives them a much stronger negotiating position to force Ukraine into larger territorial concessions.
Also that rejection of their concern caused Putin and Russia to take this as a sign of disrespect or belittling and and it caused them to go blindly into this show of force (which failed

). I don't think we should ignore Putin ego and dreams of unipolar world. They went up a tree they can't get down from and more people suffer for it.
I guess we will all see what the final agreement between the sides will look like and then in hindsight people will be much smarter on how and if this could have been avoided to a degree.