Yeah that meshes with what I know as well. However I'm pretty sure when I started on the PS2 pre-launch, SCEA dev support didn't even exist. Sony Japan probably didn't feel it necessary.
Which is probably why all our docs were in Japanese for the first three months.
It's remarkable in this context how one of Sony's primary strengths for the Playstation franchise has always (certainly PS1/PS2) been having the broadest third-party support of any console out there.
Well, this started with the PS1 because it was actually quite easy to develop for. It had good tools, the tools were cheap, and you could build your game in C.
Contrast this to the N64 at the time, which had a $1000000 buy in for a developer license, or the Saturn which was, by all accounts, a nightmare to develop for that made the PS2 look like child's play.
After that, the support comes down to the economics of numbers. Most devs I know would have gladly made games on Dreamcast forever, but (piracy/marketing/apathy) killed it, and the PS2 was all that was left.
Which is probably why all our docs were in Japanese for the first three months.