It reminds me of a review of long-distance coach services where the author praised the service and said he prefers it to rail service - but only if the seat next to him is empty. He conceded that a fully packed bus would be terrible.

I think this is generally the case, isn't it? I've noticed this with all airlines but especially in North America, load factors are far higher now than they were 5-10 years ago and it's made the experience far worse. It used to be that booking around peak times could fairly reliably score you a 1/3 empty flight and people had flexibility, no issues with carry-ons, and there was an air of calmness to the operation. Today that's a pipe dream.

Of course, you can't ask a business to intentionally run a less efficient operation but then perhaps the expectation of what customers consider convenient and tolerable was based on the experience people had with emptier planes and there's a need for some re-thinking here.