Alignment is a problem. The fantasy kitchen sink can be a problem. I play E6 to avoid things happening at higher levels that I don't care for. Wizards becoming demigods. Magic solving every problem. Things that wreck my fluff. I ignore tons of fluff that seems dumb and I don't have any problem with someone refluffing something as long as the RAW is unchanged.

But if we both didn't care for the core fluff, the warriors and wizards running around a fantasy setting trying to be heroes (mostly), then we wouldn't be here on this forum debating the quality of the details. We wouldn't care.