Huxley ultimately believes, as all artists believe, that a creative life is the only life worth living. Suffering and conflict is the fuel of all higher pursuits. In Brave New World, people are drained of this fuel. Life is easy. People just go along with the flow. But this means they create nothing. This is a horrifying prospect to Huxley.
"One must still have chaos in oneself to be able to give birth to a dancing star."
-- Nietzsche
I disagree. I mean, the combinations of education, travel, and hallucinogens has pushed me further in my art and intellectual curiosity than suffering ever has. For so many people, suffering simply stagnates them because it eats up so much mental and physical energy.
The lives are certainly not without conflict, however. Meeting social norms still creates some conflict (what, you want to be with only one person!?!). Most folks are, however, missing things that pushes them just a little outside of their comfort zone - but you certainly don't need conflict for that, but rather, just things that are different enough.