Hot in tropics...no breeze in cockpit. Winch positions & sail control generally a bit compromised. Generally less sailing performance due to changed sail plan. Windage at anchor and in storms. Increased rocking in wakes/cross-swells.
There is nothing wrong with a pilot house but as with any design, there are pros and cons. The big plus of course is shelter from the weather and cold and this is why you see more up north and far fewer in the tropics.