To quote the developer:
Well, adding an on/off switch isn't difficult. But it goes against the philosophy of the product, so I'm opposed to it from the point of view of the logical purpose of the product.
People would just enable it and not give a single care to temperature compensation.
I'd rather people learn the proper way, than try to simplify it and then acquire bad habits.
There is also the fact X-Plane is going to have this simulation built in with V12, and many people are going to be using it with many addons, as presumably it’ll be default enabled.