Sometimes there's some sort of JS/CSS rendering trick that has broken on the page. However in this case words like "I'll" still contain their capital.

In this context (not an immediate interactive chat) I find these issues awkward and disrespectful to the reader, the same as if the piece was filled with typos.

When the author treats a post as worthless throwaway text which isn't worth fixing even when they have plenty of opportunity... Why would that be worth the time of a stranger to read?

I agree — yet here we are on the front page of HN.

honestly the worst is when it’s all lowercase AND there are lots of typos.