I concur... It's simple ergonomics...
Hold your hand straight in a natural position... Put the radius in your hand with the thumb on the firing button... the Atomizer is pointing away from you. You have to rotate your hand back to get to it to use it...
So... flip the mod around, put your Index (or trigger) finger on the button... The atomizer is pointing straight at you... Ergonomically superior.
Ca is absolutely right... if our hands were designed to use our thumb for actuation, It would have been on the other side!
Suggestion... If a person is dropping their mod a lot... perhaps it's because they are using their thumb for actuation instead of using it for grabbing? A mod being fired by my Thumb just FEELS like I'm going to drop it! It's considerably less stable in my grip.
Maybe it's just me?