Seems like having the 19 best people is more important than worrying if every minority group is represented
While I would theoretically agree that merit should trump all, this is politics and everything is about perception. If the Republicans took a consistent, principled stance on always doing what is best, rather than what is a strategic political position, that would be one thing. But if you are going to cut corners (which you have to do in politics if you want to win), then this is just a good a place as any.
Everyone can pretty much agree that if the GOP does not make inroads with women and latinos, they are doomed over the long term. So it would stand to reason it would be a good idea to at least make a token gesture to these demographics to avoid yet another public perception problem.
And finally, do you really think that of the 200+ Republican house members, the 19 committee chairs are really the "best people"? I'm going to guess that something more than true ability dictated who got a chairmanship.