The opposite of why is now
Questions are good. A legitimate, "why?" is enough to change the world.
But stalling, stalling is the last thing you need. And why is often an escape hatch for people who know what they should do, but fear doing it. It's easier to ponder, to question the meaning of this or our role in where we go next.
The best answer for the stalling why is: Go.
[and of course, the best response to the impetuous, status-quo driven 'Go' is to ask, "why?"]