Private Torrent Sites

I have a question about some of these elite private torrent sites. I've heard many say the less who know about them the better, but I don't really understand why. Or why some sites limit their member numbers to so few.

With torrents, isn't it true that the more seeders there are, the faster your download? And when you're seeding, the more peers you're connected to, the more you upload, thus allowing your credit ratio to get higher?

If it's correct, these are all things desired by torrent users. Why the limited numbers?

for some private sites, uploaders are not problem, they have enough upspeed!
and they focus on safety!! this is just my opinion.

lower number of users guarantees lets say good people get invited, no cheaters, no noobs etc
also people willing to share sth with others, not only leech and seed

alot of uploaders on private sites have huge amounts of bandwidth to use... so even with one seeder the speeds are very high.

also limiting member numbers and having less people know about them makes them less of a target for the authorities, MPAA & RIAA etc.

i dont really think there's any guarantee anywhere.however rule any site might set,there's always gonna be the GOOD,the BAD and the UGLY

The more people you put into the same part. Higher chances are to get caught, get cheated, get hacked, have more hit and runners.

By limiting the memberships... it makes people value their accounts more cause some sites are hard to get into so people dont want to lose their account for stupid reasons.

Another reason I think is technical problem . Some tracker software is best with limited users. (about 50000 -> 100000) . Maybe i'm wrong .