mw13 – Firstly, I assume that you agree to the fact that divorce is a huge stigma in the frum world. Taking that fact on board, logic alone dictates that there must be a significant amount of people who wish for, but are too afraid, to divorce. It has to be! If you were terribly unhappy to the extent that you really wanted to start afresh with someone else since you can’t get over the current issues which bother you about your spouse, and you know that if you divorce her the entire community will be murmuring about you, and because your community will assume that you must have issues it will be quite difficult for you to be set-up with anyone else in the future – there is a significant chance that you might ‘stick it out’ for the rest of your life and put on a show for the world. Do I hear you saying that it will be courageous of you to do that? Who says that doing THAT is courageous – Maybe divorcing her is the morally correct action to take!
Secondly, I know personally first-hand of a few people who have stale and rotten marriages but are too scared to take the plunge. These ‘few people’ are good friends/associates – Thus I can fairly assume that there are a load more people out there in the same boat as them.
Thirdly, I’ve heard from a certain Rav who is very involved in the NY communities. He estimates the number of broken (unfixable) marriages at a huge rate.