What do you think about the theory that Dreamcast didn't fair as well because it lacked a dvd player?
I have often heard that, but remember Nintendo was running on cartridges at the time with the N64 and while not making boat loads, definitely turned a profit.
Now, to be fair, the big N had that first party line-up that no one else had, but Sega had a lot of first party potential as well and for some reason couldn't even be close to competitive.
I think the DVD player aspect is a little overblown to be honest.
Let's look at what we know about gamers, do they care what medium the content is on, or do they just care about the content?
Nintendo was running 256MB cartridges and cleaning up. (They sold at least 60 Million N64s worldwide)