Or perhaps you mean porting Classic Mac in the 90s would have been a bad idea?
I knew guys who ran early ISPs, tried it for servers, then realized they'd be better off with a Sun box and then eventually early Linux (Slackware). They were trying to run a news server off of it, IIRC.
However, the point remains that Apple ran consumer products on Intel chips for 14 years or so and this was successful. I'm trying to parse out the claim being made. Eg. Is it an argument that the timing would have been bad in the 1990s? Notable that Apple also killed the experiment around PowerPC clones around the time Jobs came back.
Apple also wasn't rolling in cash like the are today. They were struggling. They wouldn't have had the resources in the late 90's to support consumer-level x86 and the various hardware/driver configurations. NeXT was fine with supporting a limited set of configurations since they weren't targeting the "consumer" anyway. They were targeting high end commercial "workstation" customers. NeXTStep 486 cost something like $800 if I remember. The developer tools were more $$$. The people running that stuff could afford to spec out their machines properly.
What they needed to do was invest in the successor Amiga chipset to the original one. Yanking the funding for Amiga R&D in the late 1980’s is what doomed Amiga and Commodore.