I'd agree that post count is a poor indicator of skill, but at the same time, it does imply a bit of experience with the boards and the community. People with high counts are probably better prepared to tell you where to go for information, or who else on the boards can help you, so the whole adoption idea could be useful in that respect, at least. Maybe a more effective choice would be to add a directory of board users who are willing to field questions, indexed by their expertise, and a complementary directory of people and their interests.
~Joe
PS - As for 'spammers,' I think that's a bit of an unfair connotation. There's a general discussion area here for a reason, and it's not to talk plants (there's like a dozen other places for that.) If people want to post all the time to keep in touch, let them - you don't have to read it if you don't want to. The general topics are there to make this a more friendly, community-based forum, and if people are talking up a storm on them then I'd say they're doing the job they were intended to do. If anyone is justified in complaining about the abundance of general discussions, it should be the admins that have to screen them for inappropriate content.