You know, iPoker has 'beginners tables' at low stakes that are restricted to those who has signed up to the room less than 3 months ago (it's exploitable because one can just switch rooms on the network every 3 months, but let's ignore it). FTP also has 'new to the game' tables that a player can enter only until s/he has played 2K hands or 75 tournaments.
The reason why I think a similar restriction might be useful at Pokerstrategy is that players with different experience require different complexity of discussions and sometimes it's not possible in basic-level coachings that are visited not only by beginners, e.g. Collin Moshman's current series.
Speaking of my own behaviour, I'm being told I shouldn't visit them but, as they're the only chance to chat with the legend for free (except occasional Skype convos that I shouldn't abuse), I can't resist the temptation to visit and then end up criticising your crude 'beginner strategies' and asking questions that are beyond the scope of beginners. I think any other experienced member can have similar urges. And poor Collin is getting tired of explaining the differences between what near-optimal plays he actually makes in games (and we should make too if we play $5s+) and what the 'beginner strategy' tells to do.
I don't think a time restriction (say, <3 months upon signing up to PS-gy) for entrants would work well because there are lurkers like me (I earned the first SP over 4 years after signing up here and made the first post here 3 months even later). But the lifetime SP criterion sounds plausible because anyone who has raked that much without going bust and losing interest to the game likely plays and thinks significantly better than a 'beginner' and won't be interested in such coachings (because they'll contain no advanced discussions) and the restriction normally won't stop them from raking under you if you fear that.