Taking a longer view, in the case of Sega and Microsoft, rather than a third console curse, I actually argue that their second consoles, the Genesis and the 360, were actually one-off lucky flukes from companies that never really made a splash on the market otherwise. The SG-1000/Master System line also sold poorly in most of the world, Brazil notwithstanding. And people forget that the original Xbox actually sold on par with the Gamecube, and Microsoft lost a lot of money on the system where the Gamecube did turn a modest profit for the generation (the GBA was Nintendo's star performer of the time, of course.) Sega's and MS's fourth consoles, the Dreamcast and the Series consoles, were absolute sales disasters. The Dreamcast exhausted the last of Sega's finances, and the Series seems to be exhausting the patience of Microsoft stockholders and executives, especially after Microsoft spent the GDP of the Dakotas on buying ABK and Bethesda. Sega was also plagued by heavy corporate infighting between Sega of America and Sega of Japan, but ultimately, Sega of Japan were the bosses, and Tom Kalinske eventually left, replaced by Bernie Stolar. It's becoming increasingly clear that Xbox has been similarly dysfunctional and plagued by corporate in-fighting, if comments from outgoing Xbox developers like former Bethesda VP Pete Hines are anything to go by.
