There's a cost to this too, in terms of development effort. Yeah, one option isn't a big deal, but multiply this by the gajillion times that developers have to make a choice between something < 1% of their users want and what > 99% of their users want.

Backspace-as-back-button is not an "advanced feature". It's a hotkey that essentially no other software uses for the same behavior and one which conflicts crappily with the fundamental behavior of that key. It will take you, generously, a day to relearn the new hotkey. Instead you'd rather the developers maintain indefinitely an option and corresponding logic to support your existing use-case.

If you can't tell, my level of empathy for this kind of griping is roughly zero. Adapt to the new hotkey and save the complaining for something that actually matters.