What a lovely, civil exchange. (I hope that the tone on the socials at the time was just as civil).
Developer plants an easter egg. It was a good one ... and it was a reasonable assumption it wasn't gonna break anything. Several people have a good chuckle. Someone gets affected negatively by it, so the developer says, "fair play, that wasn't the intent, let's remove it". Everyone hugs it out and moves on.
I have no idea if this was the full story, or if his Twitter was aflame with negativity, but I imagine if this happened today, the tone would be much more combative than the exchange on the Stack Overflow page (eg: this HN thread, which is full of 'Easter Eggs Bad! Bugs!') -- which is a real shame.
If humour be the bugs of life, play on.