Why does it take so long to get paired up for variants?

Have any of you ever had to wait like a few minutes to get paired up every time you want to play something other than standard chess? Why is that?

players usually only play regular chess

most Chess coaches want their students to play normal chess only. 

The thing is, I don't have a coach,  so how about me and my friend go play a variant, grandmasterNo01.

Someone else needs to be looking for a game in your chosen variant at the same time and that person has to be within your rating range and you in their range. Also, there are fewer people playing variants in general, so that compounds it.

thanks martin!

Probably joining a club that specializes in your variant would help.