Why all simuls are unrated?

How about a separate rating for Simuls?

Why not? Because people cheat in simuls just so they can say they "beat a master".

Don't believe me? Here are some games where people cheated so they can say they "beat a master"

http://en.lichess.org/jkLx7Rn1/black
http://en.lichess.org/kQ6H3dcU/black
http://en.lichess.org/hWsuOVBX/black
http://en.lichess.org/SQlEXdVd/white
http://en.lichess.org/aY1iNi1i/white#40

And tournaments. Some people really like virtual points.

There is a point there too, chess for fun afterall