Life, there appears to be three main MLC approaches to divorce. Some start it early in the MLC and this is usually over fairly quickly. The second starts the divorce later on in the crisis when other stuff is going badly and then it seems to drag on for months and even years, and the third talks about it endlessly and may even start it, but never finishes it.
I am sure there are variations on this. Oh yes, and sometimes the LBS starts the divorce to protect their assets, and/or because they have moved on. Even then the MLCer can delay things almost endlessly
A friend of mine who no longer posts here has been in the divorce process for nearly three years, and mine took over two to finalise, all the delays down to my xh. But there are others who got done in a matter of weeks.
I think if you are looking for 'reasons' some of them seem to think that divorce will 'solve' their problems and they get it over quickly Others are less sure, and drag it out and also use the process as a punishment.
Just remember that the MLCer is essentially nuts, and take care of yourself. Please do not worry about your h's reactions. You will never 'win' with a MLCer. As long as they blame others for what is going in their lives and minds the principal person they direct their rage at will be you. Think of them as a very cross toddler whose mommy has just failed to produce a cookie . . . . If you think 'Ah yes, cookie rage' it is less hurtful.