They do address that in the article though.

Dowse adds that "99.9% of our community are the absolute best and it’s because of them— thankfully—that my community team perseveres. But I suppose it was inevitable that when you have a city, a few bad eggs will start a fire."

"It's a double-edged sword that comes with this kind of approach—especially with a game that's this popular. Developers gain a lot by listening closely to feedback, talking with their players, and putting a face to their names on social media. On the other hand, they also open themselves up to the masses at large. While only a small portion of said masses are nasty, the law of large numbers kicks in very quickly: 0.5% of a million people is still 5,000 angry strangers yelling at you."

Even if 99.99% of the community is amazing, that still leaves at least 1,000 people who are still willing to do/say terrible things to the developers.