Interesting conversation. I will not be judgmental, just try to give my outlook as the caregiver.
My wife is c5-6 complete quad. She has some arm movement, so she can use a power chair. Additionally, I have equipped her with a computer and necessary assistive technologies to enable it, and other things like TV and phone controllers (on her chair). So she can do a lot, despite the fact that she has no ability to even scratch herself. I am her 50% caregiver- I feed her dinner and put her to bed most nights- except when I am traveling for my job. And I also take care of all the nasty things (keeps caregivers from leaving). Otherwise we have caregivers here while I work. I work out of the house mostly, so I get trapped into a lot of caregiving. I have to cook and clean- two things I am not good at. And I have to do all the other things she USED to do.
May marked our 33rd anniversary. We have been through a lot together. Even some traumas before her injury (now 9 years ago). What didn't kill us made us stronger. I would not dream of leaving her. She is the love of my life. Our conversations were always more important than anything, and we still share the same discussions and share the same views on things. She doesn't like to go out a lot, because it is a pain, but I make her do so- eased by the handicap van we own. So, I miss out on a lot of our previous life, but we lead a different life now. And it is just as full because I look at the good things rather than the bad. She makes it easier because she has a great attitude. But she is not doing a lot to recover, and sometimes that bothers me, but I know she must have her own reasons, and has to have her own drive if she is to do so. I simply seek the opportunities when they come up.
Recently she designed our deck out back. Together with her computer, a piece of deck design software, and Dragon Naturally Speaking package, she completly designed, ordered and then oversaw the construction (me and friends). It is complete and beautiful, and she did it all herself. She used to do that before, but was not capable of doing more until I equipped her with the proper tools. Now she spends a lot of time doing other projects (kitchen is next I guess because parts have been arriving at home). The point is she found something that gives her value and reason to get up in the morning, and she kept at it. I would suggest that as mom used to say- Idle hands are the devil's workshop, and everybody needs to be given something to do. I guess we need to (as loved ones) look for those things our spouse used to do, and find ways of helping them do them- the smallest project could be the biggest victory for somebody who feels incapable.
There are a lot of assistive technologies out there, and there are even institutions that will help you buy them, or get them covered by insurance. They make life better when the injured one can do JUST A LITTLE MORE for themselves. It gives a degree of sense of accomplishment that we all need.
As I stated- I could never foresee ever leaving her. Yes, I get frustrated with the things I miss also, but, wow- look at the crap she puts up to be married to me. And she was always there for me and the kids as they grew up. And I simply remember the many things my beautiful wife used to do. Someday, we'll BOTH be incapacitated, and I don't know what I'd do if she wasn't there to help me through that. Remember that the term that quads use for us who are not injured is not just "able bodied" but "temporoarily able bodied". What a wonderful life it is to live it with somebody whom I truly love. I can guarantee in looking out over the vastness of humanity that I could find somebody else to live with who would make me even more unhappy, if that is the way I felt. And then what would I do? Just keep jumping from companion to companion until I found on who made ME happy? Not the type of life I care to lead. Sorry if that last part sounds a little judgmental- not intended that way- just trying to state my perspective on that because I've thought it over MANY times with a fair bit too much single malt scotch or beer. And I always end up back there at the same conclusion. I must admit that a few hundred dollars spent on a caregiver here and there goes a long way.
So hope that helps- I've also gone through points of depression, but I always come back full circle. The alternatives- while their grass looks greener from afar, are not really that appealing once you get fully into them. Heck- I went through points of depression going to work for a bad boss every day for ten years. So, however miserable I may be sometimes, I know its not as miserable as I could be (hah- been there, done that, got the t-shirt). Life's a journey, and I'm getting to see parts of it most can only imagine. God must like me. Oh- did I forget to mention my beautiful wife?