“Meryl Streep shouldn't have gotten so political during an entertainment event – it's not a place for politics”, one has certainly heard a couple of times in the last few days. Geeez, that's one of the lamest excuses ever. If you don't agree with someone, but cannot tacle their argument, then just say they shouldn't be so political...
So let me get this straight: “Politics is the process of making decisions applying to all members of each group”[source]. Even if you're not interested in politics, politics is always interested in you. Even if you're not political, the politics affects you anyway. That's how our species works: we need to live in a herd and we need to overcome our differences somehow.
It would be utterly idiotic to be a subject of political decisions (which we all are), but not wanting to influence them in order to live in a society that you'd like to live in. Especially if you're a celebrity, a role model, somebody who has a great power of influence over other people. If it wasn't for Hollywood – actors coming out, screenwriters putting gay characters in their shows, celebrities expressing their support – America wouldn't have marriage equality today. Their “political statements” made a significant, positive difference in the American society, and societies all around the world. So why is “getting political” considered a bad thing? It means caring about the community you live in!
And how on Earth can it be wrong to criticize some prick for mocking a disabled person? Even if this prick just happens to be a politician.