I doubt you'll catch much flak for it but nothing is stopping you from telling those people to fuck off

I think it was a recent update

What

some of it is wanting to keep the spirit of competition alive because it encourages them to be at their best. That idea falls flat because it would require nintendo to care about what sega is doing (they don't)

They're more likely to be like "Hey you like Crossworlds? We have it on our system too!"

People will keep doing this no matter what because that's what sonic was made for - to compete against mario.

Some of it is that some sonic fans feel like they've earned payback after years of getting clowned on by mario fans/fans of other IPs so when they get something good they act like this and

A good chunk of it is ragebait + an excuse to keep the mario vs sonic bullshit alive because ever since that "sega wants sonic to surpass mario" article dropped they use mario as a benchmark for whatever sonic thing is out