The Sega comparison has been made at least here on GAF however tech/game media has stayed away from the comparison because it is very hyperbolic, what went into Sega's hardware demice was much more complex and over several gaming gens that what is happening with MS. Its not comparable at all.
The thing is, it's not. As has been said, the comparison isn't to the Dreamcast, which was a dying Sega's last gasp at the hardware market, but the Saturn, which was a clusterfuck of a launch in the US, and quite possibly the worst E3 disaster in history.
The thing is, Sega, like Microsoft, didn't just make one mistake in 1995 that killed them. Like Microsoft of today, Sega of the 90s spent years slowly bleeding the goodwill of their fans, underdelivering on promises, and overdelivering on crap that their core fanbase didn't want. I loved my Sega CD, but the fact of the matter is that for a $299 launch accessory, it did not have anywhere near the stable of software it needed to be worth it in the eyes of many. After the Sega CD the 32X came around and it did well out the gate, but died a quick unceremonious death once it became clear that the Saturn was the company's future. That's not even talking about the tons of Genesis skus confusing the market, the overpriced CDX, the dwindling software lineup in comparison to the SNES at the time, and the complete disconnect from their fanbase.
Saturn then decided to piss off all but 4 retailers in the US with an early launch, piss off their fanbase with an overpriced system that had next to no games for months, and they didn't take their cometition from Sony seriously. All of these individual errors could have been dealt with in isolation, but that was not the case at all.
Microsoft is in a similar position now, coming off a successful generation where they did better than most would have hoped in 2005. They have a popular gaming service, and are generally the console of choice for multiplats. But they have spent roughly 3 years slowly alienating their fanbase, underdelivering on Kinect, underdelivering on first party core games for the 360 and overall losing focus on the people who got them there in the first place.
When you add on the hubris of a $100 more expensive console that shouldn't be, and the fact that they are pissing off retailers (I doubt Gamestop will forget the blindside, even if MS went back on it), it's easy to see how the reveal of the X1 is probably the worst since the Saturn. Sega thought they had the US and European markets on lockdown in 1995, by 1996 they knew differently, and by 1998 it was over even if we didn't know it yet.
MS's biggest advantage is that they have started course correcting early, but the DRM and internet fiascos were just symptoms of a greater problem.