Not all of this is directed specifically at you, just giving my two cents on the whole DVD debate and I like bantering with you so decided to quote you lol
I agree that the number of people who bought a PS2 solely or even primarily for its DVD player is probably pretty small but I do believe its ability to play DVDs right out of the box was a major factor in its overall appeal. An all-in-one multimedia device that allows you to play games, watch movies and listen to music was a novel idea and big deal in the early 00s.
As for price, I think a lot of people are looking at it the wrong way. We shouldn’t be looking at it in terms of “was PS2 cheaper than standalone DVD players” but rather does a gaming console with a built in DVD player offer a better value proposition than other gaming consoles or standalone DVD players?
If I was looking to buy a gaming console in 2002, what offers the better value? The $149 GameCube with no ability to play DVDs, the $199 Xbox that can play DVDs with an additional $29 add-on or the $199 PS2 that plays DVDs out of the box?
If I was looking to get a DVD player around the same time and also like to play games or have kids who play games, what offers the better value? A $149 DVD player (google search said average cost was around this price in 02) or for an extra $50 one that also plays the biggest games?
Now with all that said, PS2 would have dominated with or without DVD playback for a few reasons.
1. It was the successor to PS1 which sold over 100 million and was the highest selling home console ever at the time.
2. Sony didn’t make any major mistakes for the competitors to capitalize on and steal marketshare.
3. Year head start gave it a solid install base before competitors made it to market.
4. Exclusive/timed-exclusive home to major franchises like Grand Theft Auto, Final Fantasy, Metal Gear Solid, etc.
Without DVD playback maybe things would have been a bit closer, something like
PlayStation 2-125 million (actual ~160 million)
Xbox-40 million (actual ~25 million)
GameCube-30 million (actual ~22 million)