Sure, the official rules say that, but official rules and de facto rules may differ.
Eg. my fraternity's charter states that we will not discriminate by gender (as required for all campus-affiliated organizations). However, if someone is not a good fit for the org, they won't get a bid.
Yes, every Greek chapter on campus has that clause, but if let's say I were to sign up for NPC formal recruitment, I don't think I'd make it past the first day. :P