The problem is that public figures are exposed on social media to everyone. And even though 95% of the population might be reasonable and decent, you have those 5% who are simply not. Then you catch them on their worst day and so I am sure Matz gets bombarded by all kinds of garbage.
I have noticed this problem in other places where people have to deal with the public at large without a filter. For instance, a retail or waiter might encounter all kinds of rude people on a regular basis.
I wish there was an AI quality filter on social media. Sort of like what @dang does here.