Firstly, he toured outside US (after 1989) because in foreign territories/markets (Europe, Asia, etc) he was more successful and his album sales were bigger.
Secondly, the 1993 Chandler accusations made many of his American fans stop listening to his music, stop attending his shows, stop respecting him, etc, (which also led to his declined popularity/success there).
Thirdly, there was a technical reason: the stage (i.e., dimensions) of his Dangerous Tour was not really suitable for the US arenas (contrary to the stage of his BAD Tour which was suitable for the US arenas).