I agree that the return game is very important. Field position is important at all levels of football, but it is absolutely critical in the NFL where teams are so nearly equal. I also disagree with Thompson to a degree in that I think if a return specialist is above average in both punts and kickoffs that he deserves a roster spot even if he doesn't contribute on offense or defense. He doesn't need to be elite, but above average.
Another point. As the Texans become better at keeping control of the ball and keeping opponents from scoring, punt returns will become more important than kickoff returns. That is why they need Moses to improve in that area of the game or find someone else.