Compliments are wonderful to get. They can make us feel good about ourselves and let us know that the people around us value us. Positive reinforcement is such a wonderful thing.
Men are supposed to be stone walls and emotionless. According to society, anyway, we all know that that just isn't true. Men can be very emotional, and have feelings just like everybody else.
So it's no surprise that when somebody says something nice to them, they're affected, just like everybody else.