Because it is the only and obvious solution to any country that knew how it was? Like, it was so bad, nobody is even thinking about "oh maybe joining Russia would be coooool"?
Not sending weapons to Ukraine is appeasement and nothing else. If you are alright with appeasement, I would like you to stop your claims on Sudetenland, the free city of Gdansk and probably the Benelux region and the entirety of France.