"Hurr durr they said something negative about that thing so they're obviously OFFENDED."
No, we're not necessarily offended per se, we just think the idea of retconning the Turtles' origin story like that is a shitty idea.
And even if people are offended by it, what the fuck is it to you? Was it your idea to make them aliens? No? Well if you don't like people talking about something you have zero investment in, don't read the bloody topic.