because of Bad tour.
Do you thing Prince's ego could take coming in second?

Bad Tour
September 12, 1987 - January 24, 1989.
The Bad Tour was Michael Jackson's first solo tour. The tour began with 14 sell out concerts at the Korakuen Stadium, Yokohama, on September 12, 1987. The U.S.A leg of the Bad Tour began in Kansas city to 2 sell-out concerts in Kemper Arena, bringing in $700,000 and $200,000 more than any other artist at the venue. The European leg of the tour was kicked off with 2 concerts at Flaminio Stadium, Rome. While performing in London, England Michael breaks a world record (as shown in the Guinness Book Of World Records) with 504,000 people attending 7 sold out shows at Wembley Stadium, more than any other artist. The 123rd and final show took place in Los Angeles at the Sports Arena on January 24, 1989.

Bad World Tour figures total 123 concerts to 4.4 million people. The 16 month tour grossed over $125 million, more than any other entertainer had on a single tour. During the tour Michael invited underprivileged children to watch him perform, and contributed to hospitals, orphanages, and other charities.

You might want to find the recent Q & A with Alan Leeds. He explains why Prince didn't want to tour the US and how disappointed he was.