I'm inclined to agree. There might be story reasons they want to explore why Morty and heck, the whole family doesn't seem to be phased much or at all, or are now actively participating in violence and murders without much thought.
It was just last season where Rick implied to Morty that the reason he was participating in the purge was because he ate some food laced with .. whatever it was, some kind of purge inducing drugs on a candy bar, even though that may not have been true, the show was aware how far it went with having the innocent everyday people, like Morty, going on a killing spree. And when Summer was in the car which was protected by the alarm, and how horrified she was when the car alarm was murdering people.
Again, it might be that the show recognizes this and is going somewhere with it, but when these characters don't retain their innocence so much in Season 3, they're less endearing.
It's not like I abhor cartoon violence, but I thought the violence in Episode 4 was really off putting, especially since Morty barely had a reaction to seeing people he thought of as heroes dying left and right, and Rick being responsible really.
Rick seems particularly murderous this season too. It seems to fit the character when he's protecting himself, but he's going out of his way quite a bit this season.