Good idea to do this. Why we should do something is more important than what we should actually do, IMO. You can explain why to do something in only a few words sometimes (and the best posters do this well).
A nice side effect of putting in the thought process behind decisions is that the bad advice people complain about will not stick around that much. There may be a fair amount of poor advice posted, but as a group, we're not shy to challenge it.