That is no reason that the Automatic has to be more fun. The better emission values are due to the fact that the engine works in the most favourable rev range for a longer time because there are more gears. Furthermore the modern automatic shifts faster than by hand. If you have a manual gearbox and accelerate to full load in any gear (even at medium rpm), it is more fun. The automatic would shift and not allow full load (at medium rpm) to get better emission values.
The differences are marginal. And if you want to change gears in an environmentally friendly but boring way, you can also do it with the manual gearbox, but nobody does that.
