Disable ratings and reviews for Ongoing shows!

I think the title says it all. 

I don't really care about ratings, but in my opinion, it's time to disable ratings and reviews for shows that are still ongoing. Unless someone drops a show, they shouldn't be allowed to rate or review something, because it's meaningless and misleading as well. 

I don't see the point of rating something after 1 episode if the person will watch the entire thing. There should be a limit, like you can only start rating an ongoing show after half the season is aired.