I fail to see the problem:
In addition i dont think it would be logical to make it that way -- follow my idea: Newbie holds space -> he double jumps, after long time knowing this he finds out that holding down space button just replaces double tapping jump button. Seems pretty illogical that newbie first learns how to double jump (and all these cool things) and then he finds out how it actually works.
As long as there is tutorial explaining principle, I see absolutely no problem with that.
Also by allowing this by default you would refuse the possibility for those who wants to put some effort into it and learn how to jump. So when they first double jump they wont feel like winners but like everybody else because they just held one button and it happened ^^
Really? Is dj such a big deal to anyone? Even without scripts, it isn't exactly rocket science to figure out a general principle.
Besides, I don't care about double jumping too much. But bunnyhopping on a flat surface with holding space is a convenience, and again, all this stuff would be explained in the tutorial (if one was to be made), so I fail to see the problem yet again. You get the basic idea quickly, but you still have to take time to polish it. Warsow is a prime example, because you have all basic principles explained in the tutorial, but just because you do, doesn't mean you'll be able to use them efficiently in combat right away. And, oh yes, you dj there by default, not a problem.
Besides, it was jitspoe who initiated recent movement changes, so I guess he thought things indeed could use some improvements in that regard.