Because people like you (and me) keep responding.

I have no great love or disdain for TREK bicycles. I find the history of the company interesting, I own a couple of older models that I enjoy riding on occasion, and I have a great deal of respect and admiration for Dan Thornton of Free-Flite Bikes.
Some people take issue with TREK due to their involvement in Lance-gate. I certainly don't want to debate the level of TREK's involvement, perhaps others might.
But IMHO, if you are a true advocate of cycling and all the many benefits of being a part of the cycling culture, I think it's appropriate to appreciate all that TREK does for cycling. As a company they support cycling more (probably) than any other corporation- locally, nationally, and internationally- http://www.trekbikes.com/us/en/company/advocacy/
Two of my favorites that are not listed are People for Bikes and the National Interscholastic Cycling Association.