there is nothing terribly wrong with subscribing to someone else's mute list, the problem is when you add it as a normal feature it starts happening en mass and then it becomes the sum of all people's choices which ends up actually being bad. the distinction is subtle.
Discussion
the question when presented with this is will individual app developers think about the utility of the feature in terms of how it helps the individual or will they consider the effect it will end up having on the overall health of the network. part of the problem is that none of them ever even looked at these problems on other networks, so they will just make the same mistakes on here.