Even if distrowatch was considered to be an accurate measure of the popularity of specific distributions, it would still be impossible to tell anything from a single visit.
I visited distrowatch sometime last week and many of the top 25 distributions were going up in popularity.
Yeah, even I keep looking at distrowatch from time to time and I agree that some time ago many distros were showing growing popularity. However all the distributions going down in popularity at the same time surprised me.