"People instinctive grasp" on morality is often terrible, fallible and biased towards modernism. P:K proved it excellently where people couldn't roleplay LG paladins because they would consistently pick chaotic or neutral options and refused to pick lawful options; refusing to punish criminals and evil beings, even slavers and such, consistently going for releasing and saving everyone and expecting reward for being good bois.
In some way I think alignments became a bible of D&D. Some people think it's trash and fairytales, others think it does its job, and there will always, always be war.
I am completely fine with alignments as a tool for a D&D or D&D inspired game, and I believe they brought some great extra to D&D cosmology like Planescape.
Practically all issues with alignment would be solved by people not being retarded.
Or that, also kinda true.
Gary Gygax said:
When players began to announce their character’s alignment to other participants I shuddered. I suggested that such information was not for broadcast, that the PCs might not actually think of themselves as categorized thus, and the alignment categories were meant more to guide the player in playing his character in the game.
I followed similar principle. If there ever was an issue, it would be between me (DM) and player + alignment shifts were never an issue for me + stuff was secret.
Detect alignment spell can go get fucked tho, and was always homeruled for planar beings/fey etc. only. Then again, whole Divination school is fuckDMlol stuff.