Normally I can ignore it, but the font on this blog makes it hard to distinguish where sentences start and end (the period is very small and faint).
I think it might be adults ignoring established grammar rules to make a statement about how they identify a part of a group of AI evangelists.
Kind of like how teenagers do nonsensical things like where thick heavy clothing regardless of the weather to indicate how much of a badass them and their other badass coat wearing friends are.
To normal humans, they look ridiculous, but they think they're cool and they're not harming anyone so I just leave them to it.
it's meant to convey a casual, laid back tone - it's not that big of a deal.
Like look at the sentence "it has felt to me like all threads of conversation have veered towards the extreme and indefensible." The casing actually conflicts with the tone of the sentence. It's not written like a casual text - if the sentence was "ppl talking about this are crazy" then sure, the casing would match the tone. But the stodgy sentence structure and use of more precise vocabulary like "veered" indicates that more effort has gone into this than the casing suggests.
Fair play if the author just wants to have a style like this. It's his prerogative to do so, just as anyone can choose to communicate exclusively in leetspeak, or use all caps everywhere, or write everything like script dialogue, whatever. Or if it's a tool to signal that he's part of an in-group with certain people who do the same, great. But he is sacrificing readability by ignoring conventions.