Yes, culture fit, or 'getting along with each other' is important. When looking for people they will get along with, most people tend to prefer to be around others who seem like themselves. Given a team of all male engineers and two candidates of equal ability and with similar personalities, one male and one female, the male candidate is more 'like' the hiring engineers which makes him seem easier to get along with. And so a company which is just hiring people who 'are good at their job and are easy to get along with' can end up with a team of men.