They will very literally get cancelled by local government before any nutjob in the public gets to them.

If you skim the guidelines in the document I linked, one of the things artistes must do is submit a copy of all of their lyrics to be checked for inappropriate content. Then there's the clothing guidelines for male and female artistes, behavior guidelines, topic restrictions in banter etc.

After you pass all that, your ticket prices have to be adjusted to the local currency and buying power of the local market. 30% of your crew has to be local (understandable stipulation, but for Singapore you only need minimum 1 local to be hired and paid full salary to scale).

End of the day, we might have the facilities and expertise needed to mount a show, but the hassle is too much for too little return.