I'm confused; consoles were never marketed as computers because back in the day they weren't really much like computers at all. They had their own custom architectures and silicon, and many magazines talked that stuff up for days. Next Generation in particular, I've been reading their archives online and they go in on the technical capabilities of consoles like the PS1, Saturn, N64, 3DO, Jaguar etc. as chief selling points for both those systems and for selling the magazines (they were more hands-on in this aspect than a lot of other '90s gaming mags).
It was never really considered "bad" to market a console as a PC because for the longest time in gaming history, consoles simply didn't share much anything in common with PC architectures. They weren't x86-based. They didn't use ISAs or video standards like CGA and VGA. They didn't use the same interfaces or OSes, etc. There was simply no means to market consoles as PCs since they didn't share much in common with them. Even the OG Xbox, for as much it had in common with PCs, still diverged a lot from PC architectures to the point you could say it was conceptually similar in ways (use of a built-in HDD, use of (customized) CPU and GPU from PC component manufacturers, etc.), but ultimately wasn't similar to PCs of the time the way next-gen consoles will be today.
Maybe you mean more in terms of systems that tried to bring the idea of a PC in the living room, as multimedia devices, and failed trying? Systems like the Philips CD-i and the 3DO? I think those were marketed more as all-in-one multimedia hubs; by proxy that probably would seem like they were being marketed as PCs because at that time PCs were expanding into all-in-one multimedia hubs themselves, and those kind of consoles sought to bring that to the console gaming space at a lower price (compared to actual PCs). The problem with a lot of those kind of systems though, aside from price, was that they weren't built for the types of gaming experiences popular at the time or would be in the near future. The 3DO fared better than others in this respect, and was probably the most successful of its ilk, but that's probably not saying too much.
Other older systems like the Apple Bandai Pippin had it even worst, and that probably fits best what you're implying in the OP with older systems marketing themselves as PCs. The Pippin was literally a PC in a console shell, but it was a much older design even at its time, and a cut-down one at that. The price was also expensive, and outside of ports of Marathon there was literally nothing of quality for the thing software-wise. Other consoles like the Amiga CD32 were also repurposed older PC designs repackaged into console shells and had little to no work done on them architecture-wise to be a better fit for gaming. Those systems probably created a negative stigma around marketing consoles as PC-like in design BUT they were also extreme fringe cases because the vast majority of game consoles simply weren't being designed like that or marketed like that in the first place!
