That's one constant....people will screw anything up and complain.
It great that you've found your comfort level, and are happy to stay there. Some will be happy at a more advanced level and others will find even the Volt 78 with prefilled carto's too much complexity to handle.
I just find that the abilty to make an easy adjustment like turning the knob to where I like it something that enhances my vaping experience more pleasurable without adding undue complexity outragious expence or hassle.
One great example of how this would be useful is with the bad batch of CE3's that worked fine on the 78's but gave a burnt flavor on the X2. I had one of these and was able to just turn the dial down a tad on my Twist to make it vape great on both the 78 and Twist.
I don't think the concept of a volume knob, thermostat for your heater or stove isn't too foreign a concept for most adults to comprehend, and most will "get it" and make that transition to being able to operate a PV. As long as they don't get too fancy with it by adding displays with complex menus and just use a simple knob calibrated to save min-max values then user error will be minimized.
It shouldn't be. I amazed at what some brilliant people (these people have genius IQs) can't really comprehend simplistic things.
Let me ask this.. does dialing it .1 volt really make that much difference in a vape? Heck some liquid I vaped last night tasted different today. It was the same ce3 on the same x2.