The Sega CD was a massive failure.
30 years ago when the majority of the market was kids, sure.
The PC has had a similar kind of setup of never ending generation/no real generation dilineation for many decades too and has done well. Ask PC gamers if they would prefer the console model of being dictated when they can upgrade their setup and you would get a resounding "hell no, that would suck".
If you're selling only to kids it can be a problem, but the industry has grown up since then, even Nintendo's fanbase is majority adult today. It's not the 1980s/early 1990s anymore.