Do you think a magicians should do sleight of hand magic on stage? Why or why not?
Sure. Why not?
Of course, it depends on the specific material you're talking about.
Manipulation has been a staple of stage magic for years. Cards, balls, cigarettes, CDs, etc. As long as the things you are manipulating are visible, there's no problem.
Now... if you're talking about something like walking out on stage in front of an auditorium of 500 people and doing Tenkai Pennies, that would be bad thing.