I mean on the surface, no you're NTA for being sick of a particular artist and wanting your wife to mix it up a bit.
Buuuut the way you describe the situation has me wondering if there's more to it. When you start describing your wife as a child, I can't help but think that you've been less than diplomatic in talking about this with her.
If there's one way to get someone off side, it's to be mean about something they love. Taylor Swift's music is clearly really important to your wife, and you need to respect that. But equally she needs to respect your desire not to listen to it all day every day.
I'm a massive metalhead. My wife is definitely not. I put headphones on if I want to blast some metal, and in the car we listen to other genres that we both enjoy. But also my wife has never been disdainful or contemptful about my music, or said I'm like an angsty 14 year old from 2003 when I put some shitty nu metal on.