All the Sega stuff after the Genesis/Megadrive seemed really tied to their arcade efforts, in a way that Nintendo (and, toward the end of Sega's time in the market, Sony and Microsoft) didn't. AFAIK the 32x, Saturn, and Dreamcast were all only a little more different from their arcade counterparts than the NeoGeo was, which is why there were so many very faithful arcade "ports" on them (Star Wars Arcade and NBA Jam on the 32x, stuff like that). I've not seen that factored in to histories of the death of Sega's consoles, but wonder if it contributed in some fashion, or else helped stave off their demise.
The way in which Sega ultimately approached its console hardware business was actually similar from start to finish; you just have to look at the pre-Mega Drive consoles to see that the Mega Drive itself was the shining exception within a strategy that was very "spray and pray".
First there was the SG-1000 and the SC-3000 computer in 1983. Then there was a mostly cosmetic update, the SG-1000 II. Then there was the Sega Mark III and Master System; the Mark III had a variant release with an FM sound chip. All of these releases happened within a span of four years, 1983-1987. Throughout these releases there was a heavy focus on arcade ports, and Sega struggled with marketing the console as its own kind of experience.
When the Mega Drive came out in 1988 it was a big enough leap to be a stable target for a few years, and then Sega reverted to their previous ways. To the extent that Sega "got" their console business, it was a case of a few teams in various departments and subsidiaries that bucked the trends.
