3e had alignment mechanics. They were annoying. There were spells that hated one Good, Evil, Law, and Chaos, but usually Neutrals got a free pass or a reduced effect.
Many was the time I'd suffer some calamity because I'd written "Good" on my character sheet instead of "Uncaring Neutrality". I once had another player snicker at me for making such an "unoptimal choice".
I gave him a piece of mind, of course, but it did strike me as strange that the game seemed to want to reinforce players being disaffected jerks over being heroes.
Now maybe the problem was that there were few positive benefits for choosing an extreme alignment- even a holy sword didn't mind being wielded by a Neutral character! But then, looking over the game's history, even back in AD&D, most of the things that rewarded you for being Good, had an equal benefit for being Evil.
Then again, with AD&D, I'm not entirely sure how seriously it really took alignment. You were told that you should be penalized from straying from it, and the books seemed to make it a big deal, but then you could have your alignment forcibly changed at the drop of a hat by magic!
The main reason not to be an Evil character was that Good monsters all seemed way stronger than their Evil counterparts!