I kindof have to agree, I could see a lot of lawful people making the decision that becoming a more perfect embodiment of there chosen viewpoint and helping that viewpoint along at a cosmic scale is the correct thing - but someone who embraces individuality (like a lot of chaotic people) should probably go for being a Lich (or a baelnorn of similar).

Perhaps some people simply stay at the first level of the afterlife and never move on to the higher/lower levels - that could work I suppose.