Aeric
Explorer
Waaay back in 1E there was an issue of Dragon magazine that had a paladin class for each of the other eight alignments. The LN paladin was all about enforcing law and order, the CN paladin was all about freedom and anarchy, and the N paladin was all about preserving the balance. In its concept, it was fairly unplayable; the character was expected to switch sides in any conflict where one side had the advantage over the other.
Something to keep in mind is that paladins (as written) are not champions of a specific god; those are clerics. While a particular god/dess may suit the paladin's philosophy, and some gods may exist only to serve as a patron for paladins (like Heironeous), paladins serve a higher calling: The Code. They actively promote the ideals of their alignment. A paladin of tyrrany (LE) from UA is not simply an evil warrior; he strongly believes in the LE philosophy, and goes out of his way to show everyone around him that his way is the right way.
With this in mind, a paladin of neutrality seems to be a contradiction in terms. Paladins are very proactive characters, travelling the land, working to shape the world according to their philosophy and Code. Neutral characters by definition don't go out of their way to do anything, good or evil. They take care of themselves and their friends and that's it. Unlike in previous editions, neutrality isn't an ethos, it's a lack of ethos. And since paladins are defined by their strong dedication to an ethos, neutrality just wouldn't fit.
All of this is, of course, my opinion. YMMV, etc.
Something to keep in mind is that paladins (as written) are not champions of a specific god; those are clerics. While a particular god/dess may suit the paladin's philosophy, and some gods may exist only to serve as a patron for paladins (like Heironeous), paladins serve a higher calling: The Code. They actively promote the ideals of their alignment. A paladin of tyrrany (LE) from UA is not simply an evil warrior; he strongly believes in the LE philosophy, and goes out of his way to show everyone around him that his way is the right way.
With this in mind, a paladin of neutrality seems to be a contradiction in terms. Paladins are very proactive characters, travelling the land, working to shape the world according to their philosophy and Code. Neutral characters by definition don't go out of their way to do anything, good or evil. They take care of themselves and their friends and that's it. Unlike in previous editions, neutrality isn't an ethos, it's a lack of ethos. And since paladins are defined by their strong dedication to an ethos, neutrality just wouldn't fit.
All of this is, of course, my opinion. YMMV, etc.