If one wants to be a musician as supposed to just a drummer, it can't hurt to get involved with the band epxerience from different angles. It really depends, though. Some people "get it" without that stimuli.
I play different instruments, but that's just because I've felt a connection and atteaction towards several of them. I recently had my first tabla lesson, and though I like the instrument just for it's sound and use in western music, it's a more interactive way to learn about Indian music.
I'm also really into chinese music, and though it's gonna take me a long time to get any good, I've picked up both dizi and erhu to really get inside it.
It's the same with other types of music. In whatever music you're really into, it's not just good to get things from another band member's perspective, but it willl put you more in touch with the essense of what type of energy you're communicating and supporting on your main instrument, It doesn't have to be drums. I'm mainly a guitar player and I've always played the saxophone as well, but playing the drums gives me a practical way to get deeper into the music I already know, it makes music I used to listen to interesting to me again, it's making me a better musician and composer and it's just plain fun. It's also a way to make those "money gigs" more interesting, because there's more for me there now, because of the education I'm getting.