Actually perhaps the most important metric an airline - or any consumer business has - is the "net promoter score" It is those who will recommend the business to friends/family/co-workers over those who will say bad things, recommend to avoid. [it can be done a number of ways, sometimes using stong/weak promoter/detractor.] It reflects the ability to retain and attract business.

A plane like this is just a magnet for bad NPS. Most people who fly this bird don't know/care to know about specific aircraft, etc, they just know that they had a HORRIBLE flight. Most people don't associate it with this aircraft, they will associate the tight seats and pain with United. And it is not a small RJ, but an international plane where by and large, people expect more comfort in Y.

I don't think the respond of "I'm not flying United again" is frankly that uncommon, particularly when the association is not just unfriendly service, but actual discomfort.

I know that I will not be found on this plane in Y, and I know that I tell others to avoid it. I am not the only one.