I think that's a bit of a false dichotomy. "Just get new friends" is definitely callow, but muting someone for a while on Facebook isn't the same as shutting them out of your whole life forever. I have a cousin I follow about half the time. He's usually positive and funny and I love to see what he's up to, but sometimes he gets on a really bitchy tangent about his job so I unfollow for a week or two while he and his flight-attendant friends talk about what inferior beings we passengers are. I'd never unfriend him, because I value the connection FB helps us maintain. Sometimes a bit of distance is part of maintaining the health of that relationship. Similarly, my "new friends" are often just humor/meme pages that help me get through my own difficult times. Curating my feed works. Telling people that it might work for them isn't at all the same as telling them to get new friends.
How disposable do you view people to just up and remove a connection to all of them because you don't want to take responsibility for your own experience on a site?