I have not run or walked to support a cause. To me it is mindless and non productive. Something productive would be something like "Adopt a Highway" program whereas a volunteer group cleans up a strip of highway or road. Or where a volunteer group cleans up an empty lot in an inner city so it can be used as a playground. The race for the cure is basically a feel good effort so you can say you did something not realizing that the status of research was unchanged by your walk unless you picked up cans and bottles and exchanged them for money that you donated to feed the poor.
Exactly! Walking for the Cure is a worthless activity that makes the walkers feel good.
The walk/run is just to bring attention to the cause. The part that matters in a monetary sense is that the participants solicit pledges from coworkers, friends and neighbors -- a dollar or a few for every mile, or a fixed amount. The walkers are basically deputized as unpaid fundraisers. If you figure that the average walker in one of these big-city walks has collected twenty bucks (a made-up number; I don't know the actual figure), that's a serious effort, indeed.
History indicates that it works. Think March of Dimes. Is it the most efficient use of labor? No. But it only requires the walkers to commit few hours and their friends to commit a few bucks apiece, so it draws in a lot of people who aren't inclined to commit several hours each week or write a big check. If you choose to give in other ways, I'm certainly not knocking that, but these walks aren't worthless.