I have been married before (to a local woman, no immigration involved). We dated for 3 years before marriage. But as the wedding approached she got really weird and controlling. I discussed it with her and some others and it was all chalked up to "Wedding nerves". Well, after marriage we got a house, moved in, and things got worse. She was controlling. She had anger issues. She was jealous of everything and everyone (including friends I had had for years and up till then she had been friends with too). Life became intolerable. So after a short while I divorced her. So I do understand the concept of waking up one day to realize you have married a stranger.
That being said, I wasn't upset because she wanted a family, or a home, or any other natural progressions of marriage. There were some serious issues involved. And even with that I tried counselling and other things before I decided on divorce. And even after divorcing her I still cared for her, but I knew we couldn't live together and have any kind of stable married life.
This guy, as others have said, seems like he used her to get into the country and now that he is secure he wants out. I'm sure the topic of children came up before. I would be willing to guess that before his PR he was all for it. Now that he has it and a job and friends here, he doesn't because he doesn't want to be tied to her. And while they won't take his PR if they divorce, they could if it turns out he lied about something on his application. If I were his wife and I find he has lied to me about how he feels for me I would try hard to find out what else he may have lied about...
As others have said, you can't base everything on what one side says. But consider we are hearing HIS side and he STILL sounds bad... I can only imagine what we would hear if we heard HER side...