Ok, the thread title isn't really clear, but I don't see how to clarify in such a short space.

alignments aren't much liked. their major problem is that they try to enforce a black-and-white morality typical of classic fantasy, while nowadays people accept that they live in a more nuanced world and prefer something less simplicistic. Another problem is that it basically enforces the dm to pass a moral judgment on your character. and finally, there's all the kind of nonsense about some spells being evil by default, even when they have perfectly good uses, or hammering the evil lord to paste with a mace is good but poisoning him is bad.
many people, as a result, removed alignments, or stopped paying attention to them.
I got a pet idea to revive them in a more grey context, and I'd like to see what the playground thinks.

The idea is that you do not belong strictly to an alignment. you are not good, neutral, or evil. instead, you are both good and evil at the same time, though one of them may be prevalent.
say that every time you make a good action, or you act with good intention, you gain a connection to the plane of good, and the same goes for the plane of evil. Detect alingment then measures how strong your connection to those planes is.
That kleptomaniac character that the player insists is chaotic neutral and the dm insists is evil? well, he's definitely inconvenienced people, and he's been looking for nobody but himself and his closest friends, so he doesn't really ping as good. On the other hand, he hasn't done anything too bad either, so he'll only be mildly connected to the plane of evil. so a detect good would return nothing, and a detect evil would return a weak signal. the player and dm may disagree on whether to label this guy evil or neutral, but both would likely agree than he sits somewhere south of neutral.
The well-intentioned extremist is chasing a good cause at great personal cost and has ultimately good intentions, this connects him to the plane of good. but his actions, and his willingness to cause collateral damage in the pursue of his goal, connect him to evil. so he would ping as both good and evil. It's not a bug, it's a feature. under the normal alignment system, both redcloak and tarquin are lawful evil; in this system, tarquin would still be strongly evil, while redcloak would also give a significant signal on good. they are very different characters, and it's nice that an alignment system can differentiate them.

for most people nothing would really change. roy would still be good, xykon would still be evil. varsuuvius, before he cast familicide, would still register as neutral, by virtue of being very weak in both good and evil.
but the option to be strongly evil or weakly evil, as well as the option to be both good and evil simultaneously, could help adding context to an alignment.

the main issue is figuring out what a protection from evil spell does against those borderline cases...