I kind of see this as an artifact of older edition Paladins. They used to all be LG. Now they strictly adhere to the alignment of their patron. It makes not a whit of mechanical difference (since AFAIK there are no powers or effects that reference alignment) so feel free to ignore it.
As for Unaligned PC's? My 8th level Unaligned Paladin of Erathis would like a word with you.
Jay
Quite true. Alignment has zero mechanical effect of any kind in the new edition. Its really justs an rp descriptor for those who would have freaked if they had removed it from the game all together (which some of the 4th ed designers advocated for, from what I have read.)