It would lead to spiteful allocations (and non-allocations) and jealously; I can only see it causing resentment among posters about why they are not liked as much as others.
If we dump the current system I would be fine with no system at all. Post count may be mis-leading in many ways but it does give at least a vague idea of who is and isn't a veteran- not as a means of favouritism, but simply because when adusting to a forum it is good to know that. I certainly found it handy when I joined.