In my opinion, If the narrative: 'Ukraine is a democratic country being unlawfully and illegally annexed' is true, then it is our, NATO's, moral duty to intervene militarily.
For me, it's embarrassing that we're hanging back and watching. Being in NATO means we have each others back, not that we're unable to help non-members.
This reminds me of those stories you hear of some girl being raped on a train and bystanders either ignoring it or filming it on their phones. If we don't intervene now this will be a disgusting stain on our collective memories.
What else? If we don't intervene then any nuclear country can invade their neighbours at gunpoint without fear of military consequences.
I'm pretty sure we're being geed up for boots on the ground anyway so the point will probably be moot.