That is actually pretty dumb if you ask me.

Many pople do not care about seat assignments and for those, BA offers a discount. For us that do care, we have the option to either purchase the seat we want or use our status to get it early. This is by far the best feature of BAEC at this time.

I'm not sure I can understand in any way, shape or form how this can piss someone off enough to cancel a trip and buy a O/W ticket, which will cost a small fortune compare to the total cost of the existing BA ticket + seat reservation. Also, rebooking on an airline that allows everyone to book their seat at the time of booking this late will most certainly mean the best seats are already taken.