If DC hadn't failed, Sega wouldn't have gone multiplatform, therefore the console that profited the most from Sega games would have had less of a reason to be bought by the public.
Proportionally, the Xbox is the console that had the most "Sega console" image out of the 3 remaining, so i guess if you take Sega games out of the Xbox equation, things would have been very different.
However, you have to think how big the impact of Sega games were on the 3 consoles. Very small if you ask me, compared to all the rest. So i'm not sure how anyone can just give out a name like this.
Sega failed hardware-wise, and couldn't even get their software to be of much importance on 3 other consoles, except for a handful of titles, if even that.
I mean... Sonic with guns? How low can they get... :?