It all depends how often you do it. I flew economy only for years (still doing 250,000+ bum-in-seat miles a year) and loved it, until I reached a point (after about 3 years) where the novelty of long-haul travel had basically worn off and being away from home half the time became a drain, when I started to want to go in comfort.
I just don't enjoy long haul economy. I hate it. I didn't use to, but now I do. I suppose I've just done it too much in the past, and right now, if that's the only other option, I'd just rather stay at home. If my job changed so that I wasn't able to fly business on long flights (or WT+ on some dayflights), I'd find something else with reduced travel options. Diva-ish, probably, but I don't care - life's too short to spend a few days every month (which is how long I spend on planes) doing something you really don't enjoy.
That said, I'll never say never, and there are the occasional route I would take down the back if I really, really needed to. LHR-LAX on NZ for instance. Great product, usually empty. But they're few and far between. And that need hasn't arisen so far
Great post. Exactly where I got to - the more you fly long-haul Y, the harder it gets since you know exactly what to expect and it isn't good. Elite status does help (it's why I got it in the first place, so I could use the lounges and business check-ins), but not for the 10+ hours you could spend on the plane.
I was getting to the point where I felt I would end up stabbing some one, just because my stress levels were that high
Little minor blips you could handle no problem in a normal situation become major hassles, just because they are piled on top of an already nasty situation. And I won't even mention me in Y on PMT