Why would that happen anyway? A lot of people already came here from bigger sites, like reddit for example. If we don't federate, then why would people who are already here be pushed by something that isn't there?
First of all, harnesses work to some degree. They aren't perfect but that doesn't mean they don't work at all. I used one on my cat so many times, and he's only almost gotten out of it once.
Secondly, regardless of a harness working or not, that doesn't excuse letting your cat outside all willy nilly, still dangerous.
It's less that Newton is wrong and more like it's an approximation. Things always get more complicated because we are learning more about everything all the time, but for simple day to day things Newton is fine to be used and even taught.
You could also say it's important from a historical perspective, learning how we got from Newton to bigger and better things is important too.
I saw this same list of languages at a walk-in clinic.