I hesitated to use the word smart because it seems to be a hot button to many. It means nothing to me. I just didn't take the time to come up with something else.
When you presented the patch of dirt, my first thought was, "Awesome! A place to plant some flowers!" But to run with that anyway ....
When I tried to plant flowers, I found that the ground was full of broken glass that cut my fingers. As I worked diligently to till the soil, I was stung by bees and bit by mosquitoes. I kept at it though, because I believed it would eventually produce a beautiful garden. The dirt didn't contain any nutrients and the flowers that I planted wasted away, so I spent lots of money on fertilizer. I did everything I knew to do to get the garden to grow, expending every ounce of energy I possessed, only to find out that the soil was tainted with salt and I would never get my flowers from it. I simply couldn't SEE what was really in the soil, regardless of how it appeared, or else I never would have planted the garden in the first place. Sure, I could put in a parking lot, but I'm just not interested in a parking lot, even if someone else is. They can have the dirt, because it has no value to me. My perspective changed, because of what I learned. I used to see a place for a beautiful garden, but now I see a patch of toxic soil that will never grow flowers (in my lifetime), because of what I learned about the soil.
By your summation, then, it all seems rather simple. I'd already planned on hanging on for the next 6 years or so until S12 went off on his own. If H is going to change anyway, and he does so sometime in the next 6 years, then maybe everything will be fine. I'm only basing my opinion on the last 18, but it's nice that you have that confidence in him that he can do it. I'd love to be able to hold that perspective from a position where I wasn't carrying the burden of him not doing so. I'd give him forever to change.
I suspect the problem is that I don't want to change my perspective. I don't want to be the W that looks the other way while her H is having an affair, though I'm sure there are many that do. I don't want to like parking lots instead of flowers. I've walked a long, hard road to get where I am, and I've whittled my concept of M down to the bare minimum of basic human courtesy and respect. I honestly don't care to change that. Not even for my M. I really do appreciate the time you've spent discussing it with me though.
But to run with that anyway .... 
