It's a human psychology thing, I think.
Most casual internet use is after work-hours, so that 'work persona' is turned off, you aren't living to company rules any more and often need some ****s and giggles after a day at work, hence 'Boaty McBoatface' or other online corporate/governmental experiments. They are generally voted on by people who have spent the day working, are tired and and need to let off steam in a safe environment, and this is a fun way of doing it. It could have been a lot worse, people were surprisingly gentle. After all, this is the same public that put 'Ding Dong the Witch is Dead' at number one in the charts when Thatcher died.
Dealing with specifics is always difficult in PR, as the old saying goes, Diplomacy is the art of letting other people get your own way....