I don't know if they pay too much attention or not. That depends on them. If it distracts them, they should cut it off. If it fuels them, then hell... maybe they should read even more. I have no idea. Saying that they "pay too much attention" or otherwise would be nothing but a guess on my part.
I do think we have a particularly loud, opinionated, negative local media relative to other areas of the country. New York teams probably have a similar experience. I'm not sure other teams do, though. And that is exacerbated by the fact that the Celtics are perceived to have underachieved this year (whether that's actually the case, and to what degree, is a separate discussion). So given the environment, I'm not surprised that there is occasional friction between the players and the media.