Was it that bad back then? Since there was no internet back then I wasn't really paying attention. I had a NES, not a SNES, and anyway, I never disliked Sega. I remember in the videostore you could rent video games as well consoles, a few times I rented a Sega and loved it.
The whole anti Nintendo thing just seems so ... immature and stuff, but then, comment sections in general are like that. It just seems like Nintendo is targeted much more. I never see Nintendo people super against Xbox and PS, at least not to the point where it is ludicrous.
I know there is a theory that most trolls are just youngsters who think Call of Duty is the greatest thing on earth and think that any game which does not involve shooting is crap. In any case, I know that what dominates gaming nowadays is specs, which in a way is sad, because the graphical fidelity seems to be more important than the game itself. To me it seems, that back in teh days of 8-bit graphics the idea of the game itself was still central, because well, there were no great graphics, I think that is also why retro gaming is a thing, because the game was central.
That said, I do like it that controllers are much better these days, whenever I play old games again, the controlls often seem off, part of it might be because of errors in the emulation, but I think that perhaps games back then might not have controlled as well as they do now.
As for Sega, they bowed out after the Dreamcast; now, I never played the Dreamcast, but I heard it actually was a good console, that was superior to the N64. Then, PS came on the market the same time if memory serves me right, so that might have done it.