Wasting battery capacity and holding it to ransom like that is a cheap trick. I'm amazed they do this.
I'm amazed anyone has a problem with it and can't see the actual situation.
Customers were after cheaper cars with a smaller range and smaller battery. Rather than develop the smaller battery, tool up to provide it, and then have to worry about 2 production lines, it is much cheaper and more efficient for them to provide the larger battery and not worry about the smaller one at all.
Customer pays for a 60kw car and they get one. Other customers pay for a 75kw car and they get one.
Added bonus (for Tesla) - they don't have to worry about adjusting production for demand.
Added bonus (for the customer) - they can unlock the rest of the range if they decide to pay extra, rather than having to buy an entire new car.
This is in pretty much the same way as how car manufacturers produce identical engines with different power outputs. My wife's car, for example, had 110BHP and 135BHP options (IIRC). The 135 is more expensive by a couple of grand, but the engines are identical - just tuned differently and with the ECU programmed differently.
Tesla are not ripping anyone off.