It feels strange to defend ubuntu (I mostly agree with your view) but I recently started using it myself. Not unity of course, which is thankfully discontinued but lubuntu, which I have on a VM.

The reason is simply support. Whatever wallet I decide to compile or any other linux app will definitely include instructions for a ubuntu LTS. Not debian, not centos, not arch nor any other distro I have used in the past.

Sure in theory we could just install the equivalent packages on the other distro but it's rarely that simple and things often go wrong unless you are an expert and really know what you are doing