These rankings are based on page views and are easily manipulated. Imagine how many people click on one of the top 20 distros they aren't familiar with to see what it is, which just cements its spot that high up.
The most interesting section on distrowatch for me is the top reviewed distros.[0] It shows what the hard-core Linux users are (at least) appreciating, if not using.
N.B. It has nothing to do with popularity (number of users)
