The echo chamber problem is not unique to your tier: circle jerking is what passes for social discourse on this site. That doesn't have much to do with the issue at hand: the people who will actually be affected by their tier being changed - should have the most say in whether that happens or not. You don't want people with zero stake in the tier arbitrarily swaying votes.
Why would you want people from other parts of the site who literally in all likelihood don't care, to vote on potential permanent changes which affect people that play those tiers in tour? Doesn't really make any sense to me, sorry. Impartial and most likely misinformed users looking from the outside, probably making their choices on the basis of sweeping generalizations, without any actual non-perfunctory experience with the tier in question isn't the way to move forward here in my opinion.
Since you bring up jury duty: I think the way jury duty is setup is a complete joke - by the way the problem of "people being swayed" happens there too! When you have 12 people doing jury duty chosen at random - after excluding people with no personal stake of course from the pool - it might surprise you that all 12 of them are probably not "evaluating things objectively": in practice histrionics/emotional appeals/appealing to their personal values holds more sway than cold hard facts, unless the facts are extremely damning. It's more about theater than about truth. Doesn't sound very objective to me.
Not to mention post hearing the facts since we have no insight as to their thought process(because they are chosen at random): who's to say the right decision came out of the process? At best you go for a redo if there's doubt as to the end result being correct...in which case you go through the same process again, at worst a tier is permanently changed because we wanted to give people who couldn't care less a voice in the decision making process. We have no context as to their knowledge viz-a-viz the subject matter at hand or whether they have any qualification to even chime in on the case(being uninformed/misinformed/or not having the necessary background to weigh in on subject in any relevant way: is Pretty Bad for trying to ensure due process!).
We also obviously can't ensure they actually pay ANY attention to points raised in front of them because they're randomly picked - otherwise known as we have no idea of whether they actually are able to intelligently use information presented to them in a particular setting, or whether they even engage with the process in the first place!
So to act like this process is inherently objective, and something to be emulated when trying to search for objectivity in decision making - is straight up wrong. At best its an exercise in optics to give people the illusion, that the voice of the people's been heard - makes it look like there are more stakeholders than there actually are.
To drag this back from the tangent this went on: it's pretty easy to see why this is definitely not how you want to make potentially final decisions. Especially not when we have the liberty of choosing who exactly should be weighing in on them. Elitism is a buzzword thrown around to express dissatisfaction with how small groups with selective membership decide upon courses of action - however: to make appropriate decisions some degree of elitism in choosing your membership is inevitable, and even desirable to ensure that the correct decision is made by people who are qualified to make them.
You bring up the issue of echo chambers swaying votes within your tier? The exact same thing's going to happen even if you bring outsiders into the decision making process. People who don't play the tier much will give a quick read to the VRs and people with a lot of badges/who are mods etc. heavily influencing the vote will happen again. The people who are most affected by a decision should always be the ones who have the largest say in the outcome. Not some outsiders looking in, for their once a year sojourn to some tier they don't actually play.
