Coz being an actor gives you an advantage with regards to publicity. People will Vote them simply because they are well known to the public. Unfortunately not all people specially the masses are very good voters. They just vote base on popularity regardless of their achievement or knowledge or even educational background.
I'm not on Erap's side but as I've said all the politicians are corrupt, none of them are not. We just have to settle for someone who is less corrupt. Erap was charge with jueteng money, so what it's gambling money anyway. Unlike GMA who took money directly out of people pockets. Even the people who were part of ousting Erap (like Cori Aquino) admitted she made a mistake when she sided with GMA on Edsa 2.
Anyway, I just hope that all the winners will do more good than harm in the coming years. God bless us all.