Is asking for money as a gift rude?

So I was watching teen mom YP, my guilty pleasure... but on the show one of their mothers had asked what she wanted for her birthday, and she said money. Just money. The mother was like really, I want to get you something. But she demanded money. I couldn’t help to think it was a bit selfish. Do you think asking for money rather than a gift is rude whether it’s for a birthday or on Christmas? Does it not seem like you’re just trying to gain rather than enjoy? Maybe because I never personally cared what I get as presents, I just enjoy the thought basically.