One point that I haven't heard mentioned is that keeping the handles presented uses power (even if you don't have the handles with the lighting). As I understand it, from another thread discussing why the handles are safe and won't crush your fingers when retracting, the handles are held in by a spring and extended by activating a motor or solenoid, working against the spring. So the handles retract after a short delay to save energy. Probably not a huge amount of energy, but it is coming from the 12V battery. When a door is opened, all the displays are also activated, which likely use much more energy than the door handles, so the extra energy use for the handles is probably moot. In contrast, when opening just the lift gate, the displays stay off, so it is a different energy profile.
Second point is that retracted handles and locked handles are separate states. So if the time delay for auto-presenting after a retraction were increased to 10 to 15 minutes there would be no great harm since touching the handle would initiate presentation, just as happens if auto-present is disabled. In an ideal world this delay would be configurable because some folks might feel that auto-present is broken if they return to the car without auto-present, even if they are away only a couple of minutes. I would guess that each of us has a different threshold for trading off unnecessary auto-presentations vs our minimum time to dash into a store, etc.