The Time Traveller expects to find a civilization that is far advanced beyond his own time when he arrives in the future; however, what he finds is quite the opposite. He is disgusted by the Eloi's laziness and intellectual limitations and wonders where humanity could have gone wrong to cause people to devolve in such a way.
He first concludes that COMMUNISM is to blame, since it would eliminate competition, without which there would be no need for invention. But after discovering the Morlocks he settles on a new theory. CAPITOLISM is to blame for the degradation of mankind. The Eloi developed as weaklings in every way because, as upper class, they had no need to work their bodies or their minds. The Morlocks became more like apes and very physically agile because their social position dictated that they evolve with those qualities in order to survive in their initially subservient role. Ironically, the lower class Morlocks became stronger than their overlords because they were the ones who had necessity. They had to maintain some technology in order to survive.
So, I guess the point Wells was making is that necessity breeds excellence, and luxury breeds weakness.