The article seems to me to be less a chronicle of why
than of how
. Sure, the Sammy saga and the death of the Dreamcast were pivotal points in Sega's fall - but those weren't causes, just the inevitable result of events already set in motion.
Sega was not a coherent company. The Americans and Japanese were developing systems without even knowing what was going on in the other half of the company! That is not a way to operate, and it manifested itself severely in disasters like the halfbaked 32X and the haphazard development of the Saturn. They lost the support of developers, retailers and consumers alike, and with the Dreamcast they presented nothing that was good enough to lure them all back.
It's all well and good to make trite statements like the Dreamcast was about fun and it failed because people hate fun, but the reality is that it was a system that was incapable of appealing to people. Quirky and innovative games do not make a system. People tried to draw a comparison to Guitar Hero earlier, but that comparison is fatally flawed in that Guitar Hero has the strength that you can pitch it concretely in a single sentence: air guitar made real. Much like the Wii, just SEEING someone playing Guitar Hero is enough to give the visceral impression that it is a really fun game. No Dreamcast game can be so simply and effectively marketed - not Space Channel 5, not Shenmue, not Rez, not Chu Chu Rocket, and so on. With Sega's brand power exhausted, the Dreamcast's ability to make its case on its own, and a lack of heavy hitting developers behind it, it was really doomed from the start.
Sega was whittled away by its incompetent management and outmaneuvered by Sony. They needed to prove the viability of their platforms and the strength of their games, and they did neither. Whether their games were demonstrably fun AFTER buying the console and its games is completely irrelevant; without the strength of a proven brand, the Dreamcast's success hinged on making its games obviously fun through demos and marketing without the benefit of a console purchase, and they utterly failed to do so.
It's also worth noting that the whole hubbub around Sega losing their autonomy is a red herring. They were a subsidiary of CSK for decades, who (if Wikipedia is to be believed) dumped $40 billion (!) in cash infusions into Sega over the years to keep it afloat. This was not a sane situation, and it ended two years after CSK's Sega-loving
founder died in 2001. Sega was a grown-up infant company living within the happy bubble formed by Okawa, and as soon as that ended the adjustment to reality took force and Sega hit the ground hard.