At first I thought fallout had a reasonable point to make, but then broadsword nailed the argument very well.

fallout says:

the only problem would be that any serious fpser would turn it on, rendering the old option obsolete

@mra
broad only repeated what i had said earlier

... says:

This game has a lot going for it, this fix would make it that much better.

I'm still a little bit stunned that the official response is "lol no 3 buttons".
Especially when by default, it is three buttons, only two of those buttons do the same thing. (Mouse2+Space)

All that being said, I don't really care enough any more to argue this further.
(Unless someone can come up with a counter argument that doesn't make me roll my eyes.)
I wish Nadeo the best of luck in this endeavor, even if they are doing it wrong.

I probably will buy it eventually, I really enjoyed the editor.

broadsword says:
Making it an option is probably out of the question due to balance, I'm afraid. Being able to sprint and jump individually offers an advantage of flexibility compared to having the current setup, without giving the separate-key players any disadvantage against single-key players. Thus, everyone (players who deliberately want to fight against the odds not included) would have to swap to separate-key mode to have equal odds.

So I'd say it's either the one or the other. Which one comes down to personal preference.

Indeed, it can totally overthrow the whole game experience.
Being not able to instantly sprint is a factor which adds a bit of difficulty as well, especially noticeable in time attack maps.

I wouldn't have mind separate keys for this, tho, but everyone should adapt to the new set-up which is quite different. Currently I got used so I'm fine with it.

Don't forget tiles like sprint pads, those are made to 'instantly' allow you to sprint, same for caves.