I think the girl has made the right choice-religion is the foundations we usually build our lives on-what we do, how we live etc. Plus, if they did get married and say he stayed the same...e.g. did not see the importance of religion he would eventually influence any children they had-the kids would grow up in a helter-skelter of religious conflict. I've seen it happen, ain't pretty.
On the other hand, maybe this guy will now realise what he is losing in terms of a women who can put her faith before a relationship and maybe he will wish to look at religion from a different view point and maybe just maybe they may end up together?
I've seen many people who would class themselves as none-religious and after a pilgrimage to Hajj/Ummrah they changed completely. One even said he felt lost, even though he knew what he wanted which was inner peace. He just didn't know how to love his religion more than the nightclubs, different girls for different occasions...I must say it was a slippery slope for him but now hes a transformed man.
Moral of the tail-the dude may not be into religion today but one day down the line he may become more involved with his religion.
It's always a bad idea to get married and think the person will change because you are basing everything on an "if" which may never happen.