Originally Posted by
entropy
AC is even more restrictive (paid J only and only their metal). But LH allows their HON members access as well , so there is "membership" , and now AX Cent's though its a limited in #'s. One could imagine they could offer polaris memberships if they wanted to (at the high price point) and in limited numbers. There are plenty (enough) of domestic flyers/or ppl who travel a mix, who would appreciate the step up... and would be willing to pay more.
AC SS lounge is actually for paid J and flexible award tickets. But AC SS is really designed to be a departures only lounge, since you can't use it on in-bound connection or arrivals. So theoretically, if UA wanted to limit capacity, they could also limit arrival access for Polaris passengers, and open it up for more exclusive paid access (?). But I'm really not sure that would really impact the numbers.
But at the end, I think it's too complicated to tier and bifurcate everything. So it's either everyone suffers the same with high capacity and sub-par experience, or you start tiering and cutting of people off that a small minority who gets cut off will make a huge stink about it (like the DL club access on arrival).