My point wasn't whether I was right to get out of my other M. I am positive that I did the right thing there. My point was that we are never in a position to reliably guess what someone else will do or not or what they will do if driven far enough. That is what you are struggling with. Is endless mediocrity in a R enough to cause someone to leave and feel justified in doing so. Some would say yes.
After a 10 year M to a very troubled man I read some book by Dr. Phil where he suggested that what constituted enough of a reason to leave was whether your own self respect and personal integrity were at stake. Is it? In my current M, I feel there is a great deal to work with. My H is a good man, a loving man, a good Dad. He isn't as sexually demonstrative as I would like. He isn't as forthcoming about personal feelings as I would like. That isn't enough to leave. My self respect requires that I address it and try to make it better. That is what I am doing. Spiritually I believe that my marriage is a sacrament. I have a responsibility to God to do my level best not just to stay married but to do so productivly and happily for both H and me. That keeps me in the game too.
It sounds like you don't know why you are there anymore. What does "for the kids" entail? There are many ways to keep a family intact "for the kids" without doing the rollercoaster ride of trying to fix marital problems. Do you want to fix things or are you just hanging out waiting for them to grow up? It sounds like you have some decisions to make. Maybe some personal counseling?
