"Mastery and critical acclaim, just as for music and literature." Well, he clearly had "mastery", so I guess the acclaim he achieved doesn't count because it wasn't from the right people.
People who have studied art in depth, who know art, dealers and museum curators and art collectors, the critics and opinion leaders, do make or break an artist. Popular acclaim and critical acclaim are not always in sync. Works that were viewed as abominable in their time can come to be regarded as possessing mastery and great beauty, sometimes centuries after the fact. Works that have been produced in great quantity for publication that are somewhat formulaic have seldom been regarded as art. Add a certain Alfred E. Newman cartoonishness to many of the figures illustrated, and you have an even greater issue with achieving critical acclaim, no matter how technically proficient.
