>>57812842But Eevee is an outlier, with the "growing up and making up a colorful cast of a family" being popular archetypes that probably boosted the popularity as time went on.
You could blame it on tpc being incompetent at making fun/interesting quadrupedal Pokemon. And they must have noticed that their bipedal, more humanoid, Pokemon more often became hits. Like Lucario and Greninja, for example. I wonder which Lycanroc form is most popular?