Why I hate champion mastery.

So Riot released this new Champion mastery system, which is overall fine; however I hate the outcome of this BS. Every time I get into a ranked game, I have at least one player on my team who has rank 4-5 on a champion, and they in turn want to show off their shiny new badge. It is fine if they're going the designed roll for that champion, or they know how to handle the champion in another lane; however, when I see some 5th pick r%%%%% pick jungle just because she has rank 5 champion mastery, I get cancer. So please, just because you hit Rank 5 on your champion mastery, doesn't mean you can make LCS big plays as adc .