Its designed for apple and not windows. Note the presence of a command key. Apple calls the backspace key a delete key even though its not. (It may do delete as a shift option.)
I personally loved the old Sun keyboards that backspace and delete right above each other so you could fix the most annoying^H^H^H^H^H^H^H^Hcommon terminal problem by just moving a finger instead of screwing around with tty settings.
I mean, that's true if you think of a space as exclusively a character. In the physical meaning of the word, what exists in place of the original character is now an empty 'space'. In some pedantic sense you have truly added space where there was once none.
Consider the behaviour before or after either newlines in plaintext or paragraph ends in word processors. Also soft wrapping. It is truly a deletion now.
Historically the backspace key is literally that, moving the typewriter's carriage back (when the space key moves it forward).
On current computers the space key now inserts a "space" character instead of simply moving the cursor a step right.
Backspace isn't symmetric to that anymore, as it doesn't even insert a space back but deletes backwards, so it is (pedantically) a misnomer.
And this is true for "modern" computers, older ones were closer to teletypes and would move back for overwrite (e.g try vi compat mode).