He's been my favorite artist for such a long time and as a fellow drawfag I love that we agree on almost all cartoon dudes that we like.
Don't keep up with the whole deletion thing so I wouldn't have any idea about it, definitely not the only good artist that does this. It's as if the better you get, the less secure you get about your own works for some reason, not saying it's his case necessarily but it's been that for me and others.
As for the people who complain about him making cartoons a priority, he probably just likes it more? It's also obviously a lot easier and faster to draw and you wouldn't believe how insanely popular it is, anime popularity aside. Clearly not the preference here but still, it is what it is.