Those of us that did not vote for this Conservative government may feel shame (I certainly do) but the UK is a democracy and the government in power reflects, to a large degree, the sentiments of the general public when it comes to migration and charity to refugees. The latter of which is often in short supply.
In terms of the practicality of fleeing Ukraine for the UK, I take your point about distance, and wouldn't imagine that we would be a more popular destination that countries in central Europe. At the same time, the fact that only 50 visas had been issued by Britain to refugees from Ukraine (at the last count I saw) is pretty embarrassing if you ask me. We should do more and better, but we get the government (and by extension, the policies and laws) that we deserve.