john,
biggest problem i see is that unless you are checking ip addresses, anyone can post multiple times and skew the results. and you can't even verify if someone has pd, the severity of their pd nor rule out the placebo affect. can't verify anyone took tumeric, they might be taking something else or a much weaker form, totally unintentionally.
as far as exercise, i always feel better after exercise, but i've also taken more sinemet so i can exercise better, so what is the affect from?

you can rail against big pharma all you want but i see a lot of small organizations doing small trials on exercise at least and some supplements and MJFF is funding a lot of small projects. big pharma certainly isn't looking at forced exercise but the researcher who initially did the phase1 is doing a phase2 with $500,000 of funding and i think is looking at the slowing progression aspect.

secondly, there's no way to prove you accurately collected/analyzed your results. as far as slowing progression, how can you even think of trying to prove that just based on a honor system of reporting?

statistics from an anonymous population are very hard to verify. i don't know about anyone else, but my pd symptoms sometimes change 50% from day to day, hour to hour, i wouldn't even attempt to report that a supplement or exercise or any other activity made me feel better until after at least a month of taking it.