Why do some guys get so whipped by their girlfriends?

I have seen acouple friends who are completly whipped by their gfs. I dont get why they would let this happen? It seems they do whatever there gf says or wants( for example one guy when he was going out with a girl she always made every decesion for him-whenever they went for lunch/dinner she would always order what he was to eat-a few other friends can,t go out to meet up with their own friends to socialize without it being ok by their GF-Im not saying a guy shouldn,t comprise or anything- however I don,t get the one sideness to these type relationships.