Actually, I don't see why they did it, this would be something like this:
I buy an Electric Vehicle, it runs fine, then a few years later the battery is degraded to say 75%, but still usable for my daily commute as that still gives me about a 75 mile range, but the manufacture decides that because the battery is degraded to 75%, they are going to make the car not travel at speeds higher than 45 mph, even when the battery is fully charged and they claim that it may turn off randomly if they don't limit it like this.
Now, we all understand if the battery is down to 5%-10%, limiting the speed until it is charged again makes sense, but if the battery is fully charged to capacity at 75%, then full speed should easily be able to be achieved. What Apple chose to do is always limit the speed if the battery is degraded, not just when it got down to 5%-10%, plus Apple never gave any indication that it was doing this. In my EV example, when the battery is down to 5% or so and the vehicle is limiting the speed, there is a clear indication on the dash that this is happening so you know what to do to correct it. If Apple had been honest and upfront about it, you wouldn't see near as much outcry about it.
