It is clearly a deliberate choice to send the signal of conforming to a particular type of non-conformance. It’s a costly signal because most people will see it as having the emotional maturity of a child, it signals to others that given their social status they can afford that self imposed handicap.
It's rarely the mature who talk about maturity.
years and years and years of ptorrone's posts aren't capitalized, though. it's not like they suddenly decided today, for the purposes of this post, to change their writing style.
in any case, i prefer to decide whether someone has the "emotional maturity of a child" based on what they say, not whether they push their shift key.