Ow @nmalove, it is nice to see you around :)
Yep, lack of intimacy can truly go from being a minor issue to the problem that actually dives people to separate. And, the way I see it, it is mainly because, like you said, people just go into their shells and brew resentment for the other partner, making their own lives ever more difficult. And then, here it come the point you addressed, when this happens there is little compassion left. It truly becomes difficult to move on from there.
Thank you for your nice wishes!
You too have a nice time and some fun during the coming days.
Take care :)