I mean personally I like to pay attention to the RT score of a movie, especially if I'm on the fence about watching something I'll check to see what critics thought. If I'm watching it anyway, I'll lower my expectations a bit if it's rotten. If it's fresh, I can go in knowing that it has quality though I might not come out agreeing (although my opinions generally align with RT). I didn't find Batman v Superman an exciting prospect (I don't really like Batman much and MoS was only ok for me) before its release, but I was a bit on the fence about it and seeing the RT score confirmed that I wasn't going to watch it.
Their TV scores I find myself disagreeing with a lot. Season 4 of Arrow a 96% while Daredevil season 2 a 76%? Hell no! Arrow is crap!