I know from experience this can be tough... and I've been in the flipped gender situation: from the sound of things, my husband is very similar to your wife with regard to hating every job, then looking back with slightly rose-colored glasses once in the next job he hates. (He doesn't cry, but complains a LOT). It can be really frustrating and difficult to be in the position of sounding board when there does not seem to be any situation in which your spouse will be truly happy. (Although I must say, some aspects of your wife's job do sound pretty intolerable) I mostly do the same as you, just listen and provide full support for whatever decision he feels is necessary. I also do try to gently remind him of the real history when he talks fondly of previous jobs he hated... mostly to remind him the grass is not always greener and to try and find the good stuff in his current situation where possible. I do hope there is something out there where he can be, if not exactly happy, then at least hate it less. I guess the only silver lining is when your spouse feels that way about work, it's pretty easy to get them on board the early retirement train!
As to the crying thing: I am a major leaky faucet. Sappy TV shows, heartwarming commercials, you name it. My response to being super angry and frustrated is also unfortunately often tears even though I want to yell instead. (and I think I have a normal hormone balance, although of course the tears do happen more readily some times of the month than others...) However, I almost NEVER cry or feel like crying at work, and when a job has gotten bad enough for me to be on the brink of tears on a regular basis I definitely take that as a sign something is very off and I need to get out. So then I do what has to be done to make that change happen for myself. Which has happened twice now, I'm actually currently on a mini-hiatus exercising my FU stash for the first time ever to get out of a terrible situation. (The other time I was able to line up my next job first, ironically the one I just had to leave.) But it took a LOT to push me to that breaking point and once there it's very hard to switch back into optimism, even though I am relentlessly, almost obnoxiously optimistic most of the time. So if your wife has previously not always cried about work and has started more recently, she should probably make a change asap. Sorry, this was way longer than I intended, good luck to you both!!