I don’t see a point in discussing what motivates people to either part from or stay with their spouses and children.
If I had either, I would not go to Mars. End of discussion, because aside from stating what you yourself would do everything else is just speculation and banter.
It’s useless to sit here and try to figure out what everyone else is thinking. Take for example Kamikaze pilots. They almost all had families and decided to leave them behind too. We may call them crazy but their military called them heroes. Morality is subjective and it is your place only to decide what you would do, not to judge others for what they decide to do.
So what happens if after a couple of years or so we find out that Mars just isn't that interesting? We are human and after some time the amazed factor of living on Mars will fade.
The funding will stop, supplies will not longer be sent, and if we are not self-sustainable by that time we will live for about 20 or 30 more years (which is the expected lifetime anyway) until our equipment breaks down to the point where it can’t be repaired.
I personally intend never to let that happen, because one of the things I will most adamantly request as a supply is a good 3D printer. There are proper minerals on Mars to make plastics so we should never run out of printing material, and should be able to produce whatever tools we need. Plastic won’t work for every patch that would need to be made but we should have enough of those parts to last a long while. A metal 3D printer would be nice as well.
If funding was to stop after only the first mission, it would likely not shorten our lives that much, if at all. And in 30 years a monument will be built near our landing site to remember us.
L. Spiro