Is some of the cast losing their ability to shed tears during crying scenes?

In my opinion, it's not the cast as much as it's the characters. They're desensitized. It's like when you watch the Walking Dead (coolest show ever!). In season 1, and Rick kills a zombie, you're running to the bathroom to vomit. In season 2, you're used to it and at most you think, "Eh." But by season 3, you're yelling at Rick saying, "You go Rick! Kill that zombie! It deserves it!" You're used to things like murderous zombies sneaking up on your favorite characters (I think Rick and everyone else are going deaf. How does a zombie sneak up on you?). In Once Upon a Time, Snow, Charming, Regina, Henry, etc. are used to people trying to kill them. Emma is always crying because she is the Savior, Chosen One, etc. Everyone is always counting on her. Talk about stress!... Anyway, that's my opinion.