"Why not" because..
If you're a creator and you're given an opportunity to create in the field you're trying to make a name for yourself, most likely you're going to be interested, regardless of your personal interest in anthologies. An anthology is a place to showcase your work along side others. Its a way to get your name out there. It's an example of what you're capable of when given a shot.
I guess I feel like I'm not sure I understand your question. I wish you'd elaborate more on your own thoughts about anthologies, and what answers you're actually looking for from others! If you just want to chat about anthologies, thats cool too. But it's pretty straightforward, right? It's just a collection of stories. Storytellers are interested in telling stories, an anthology is one way in which to do so.