I think the solution that has been anounced for 5th Edition, alignment only for outsiders and special monster with all humanoid characters being neutral, is the best and most practical one. No more alignment debates about player characters and no more detect villain spells.
Hmmm, we've been doing that for years...did we have a house rule or something?
Anyway, I like that solution. It allows me to have both styles of play. Subtle nuances of behavior i.e. indicators etc., and actual forces of malevolence and good.
The combination of the two "ends" of the spectrum make for good

game play.
A fountain of pure Good located in some obscure place that can be tapped into.
A baker who bakes children doesn't detect (although he might have a "flavor", baking kids is pretty bad)
And when a normal person does detect as an alignment, you KNOW they have been infused with some significant




. For good or bad.
But the best was when they ran into a floating pyramidal shape of force* that radiated law. It made the chaotic folks uncomfortable, and even the neutral dudes had "maybe I should follow the rules" thoughts.
*my modrons are composed of force, levitate, telekinetic (no goofy hands), and are really unnerving when they decide an area needs their attention. I think the word is implacable...hehe.