He is suggesting that the admins make it a rule that people who are not part of a faction and are not giving feedback themselves stay out of a factions feedback thread. Meaning, he doesn't want to see people who are not faction members responding to posted feedback.
I'm bias on this, as I tend to do exactly what he is wanting to prevent. I'll voice my opinion if allowed, I've done it and had the faction leader ask me to STFU. Which I did. I've done it and had the faction leader thank me. I don't see an issue with a third party reading the feedback and putting their two cents in, as sometimes another look at something helps all parties.
Faction leaders can easily enough ask a moderator or admin to tell someone to shut up in their thread. If the mod or admin feel the request has merit they'll do it. If not, they won't. Like I said, I've been on the receiving end of both sides.
All in all, in my eyes, the suggestion is rather stupid. There is no problem with having third parties drop their thoughts in, so why ban it?