If you're famous, it's hard to not have to see a lot of comments. Sure, you could set it to "only people I follow." show up in your mentions and everything. But that is also a little dickish cause you shut fans out.
I wish they'd find away to stay on Twitter for the fans, but at the same time I understand. I wouldn't want to deal with toxic idiots either if I was famous. They just need to take time away, and figure out away to handle it and work on it and learn from it. Cause it would be bad to get to the point that they make themselves look like idiots by firing back. Twitter is the least of their worries anyway, they need to focus on not having whoever had those shitty punches to get better.