Because I have lived here over the years (before I met my gf and got my son) and have large parts of my friends here.
Because my gf have a job she really loves and didn't want to move with me right away (but maybe later)
Because sometimes you have to think strategic about your families future. (of course with the danger of destroying the very family you are trying to create)
Before that (up until a month ago) I was with them every day.
My point is that unless your spouse is in on it then it's never going to work.