I think it's the wimp comment that riled a few guys. ATC isn't going to clear you to a lower level without making sure you have seperation. We ask for lower or higher all the time due turbulence, most of the time we can wait for them to check with another sector for conflicting traffic. The guys on the ground don't know how bad it is, or that you need immediate descent. If its bad enough that you're about to run the airspeed indicator out the bottom and plummet from the sky declare the pan, or mayday..turn offtrack and down you go.
You can sort the rest out later and keep an eye on TCAS in the meantime. ATC won't give you a clearance, nor should they unless its safe and legal for them to do so. If you want down before that, do what we'd do in any other situation that warrants it, declare an emergency, take your own seperation into account and descend.