Yes, it is great to give a thumbs up to show the answer is appreciated.
And sometimes it feels a bit rude when you answer someones question the best you can, but don't hear/see anything back.
You try to help someone by answering the question, but sometimes it looks like the question asker doesn't appreciate your answer, which makes it feel like a waste of time to me.
Although I think the thumbs up and down should be blocked in religious questions, because so many thumbs up and down are given because of religious differences or commonalities.
Which can make the debate more spiteful.