Two things about backdrops.
1. Studio backdrops are not cheap. A single color muslin backdrop can cost up to 30$ and the fancy ones with patterns can cost even more.
2. Backdrops take space. No matter how you look at it, each roll of seamless or fold up fabric take space. It is especially "bad" if you're using seamless paper. I mean those rolls are huge and having just a few of them will get you a 'sad smiley' with your significant other.
The easy solution of course is to use a black backdrop; a white backdrop and some magic to get all the rest. (If you've already gelled flashes till your head popped, skip right to the pattern part).