I can't imagine it hasn't been said hundreds of times by now...but that's a pretty bad idea. I've only just broke 500 but I've played silver way before this, and I've done pretty well with my groups. I don't plan on playing any higher, because I recognize I don't have the skill for it really. I don't have it now, and I don't think I'll have it at rank 5000. I promote all the time, because I do like starting fresh and making small tweaks as I play, but I know a lot of (subjectively) lower N7 ranked people who don't promote because they have their characters where they want them, and where they have already been proven to work at those higher difficulties.
I'd say at best, you could say that nobody should play above Bronze with an N7 of less than 20. For all you know, that 20 could just be one character that an individual has maxed, and continued to play ever since, ignoring all other characters, but could otherwise have maxed things out.
I don't think you really thought this one through...or you're just trolling everyone.