This is correct. An electronic switch is just a set of momentary contacts. Its up to the driver to interpret those impulses. The driver can be programmed to react either when the switch is closed (pressed) or when it was opened (released), or to do a certain action based on how much time has elapsed between each event (long-presses and such). None of that is controlled by the switch itself.
That out of the way, I agree with you completely OP, a short click when the light is off should turn it on. Period. Those silly UIs that require a longer press from off are dumb. Long press from off can be given a function, like Zebralights that use it for a low mode shortcut, but a normal press should also turn the light on. Zebras go to high with a “normal” click. Olights were mentioned above - those go to the last memorized position on a “normal” click. So do most Nitecores.
In my view, having a longer click as a switch on is a safety feature, so your light doesn’t easily turn on in your pocket/backpack… could drain the battery, or in hotrod case perhaps a fire/other damage.
It can be a good thing or not, depending what you need from a light. It would be nice to be able to choose which you prefer or to be able to do a simple mod to change it, such as the pencil trick across a cap used to create the delay.
I see where you’re coming from, but I’d much rather have a lockout mode that I can switch on and off. Those are becoming quite common. I’ve got several Olights with lockout modes and the last few Nitecores I bought had one, too.