Why should Apple always seek to rationalise their laptop range?
Threads like this always seem to throw up a diversity of opinion and requirement which contradicts this strategic direction.
Apple is one of the largest hardware manufacturers in the world - surely limited diversification would be feasible as they would continue to sell massive volumes of all variants.
We don't all necessarily need or want anorexic laptops with Haswell / retina / SSD. Why not retain and update, at little / no expense, the current MBA / MBP lines, adding the higher performance 'Pro' machines at the top end, and perhaps a cheap ARM powered lightweight at the bottom end?