A friend of mine has been separated for eleven years... neither she nor her H wish to file D... her thoughts are on the money... I suspect that it's also an issue of either having to rehash the agreements they've made or having closure that neither of them really want...
Either way, as my friend's sitch can attest to... sometimes... we don't even get the luxury of D... and limbo really has to be a state of mind... that we choose to dump... and get on with our lives...