The website is not presenting this as just having fun, but rather making the strong claim that it is actually better than the writing system we've been using.
Making such very strong claims ("I've come up with something better than what civilization has produced thus far...") naturally invites debate, especially when they seem implausible on their face and aren't backed up by a very solid argument. There would be a lot fewer negative comments if this were presented like "hey, look at this neat game I made up..."
I’m not seeing your quote on the page, and I think that drives my point home: you have created a narrative for the post that doesn’t exist. I mean, come on. They’re called “dotsies”! Does that sound like the name of a font designed to replace ours, by someone who honestly thinks they’ve advanced civilization? Or does it sound like someone having fun?
Making such very strong claims ("I've come up with something better than what civilization has produced thus far...") naturally invites debate, especially when they seem implausible on their face and aren't backed up by a very solid argument. There would be a lot fewer negative comments if this were presented like "hey, look at this neat game I made up..."