Answers (1)
How many observations of this alleged phenomenon have you made?
Outside of the homestuck fan circle's typing quirks, and possibly "nigerian prince" spam which would come as no surprise given the writers are foreign, stylistic choice seemed reasonable for those few instances.
Tldr eyecatcher.
Seems to be called "start case" or "title case", which ought to be the default in a text processor's headlines, so there's that context too.
en . wikipedia . org/wiki/Letter_case#Title_case
www . grammar-monster . com/lessons/capital_letters_title_case.htm
www . grammar-monster . com/lessons/capital_letters_in_advertisements.htm
It's mostly people of the baby boomer generation that see doing it. None of which have been foreigners