Actually he never said anything about PS1's success at all this quote has been twisted he was asked about the rise of JRPGs and fans of the genre and his response was as follows.
"[People who play RPGs are] depressed gamers who like to sit alone in their dark rooms and play slow games,"
https://uk.ign.com/articles/2006/03/14/top-10-tuesday-wildest-statements-made-by-industry-veterans
https://en.wikiquote.org/wiki/Hiroshi_Yamauchi
PS1 was never mentioned at all in the quote.