First of all, I think they mean "excess" hair, as in the stuff that lands on the floor after it is cut (although even that is not entirely clear).
"Excessive" hair, by comparison, lies in the eye of the beholder: "Her hair is just TOO much. It's so frizzy I can barely see around it. In fact, I'd like to cut it off and send it to the Gulf Coast." (I do hope the hair donations are voluntary). Let's face it, in a humid July in Nova Scotia, any hair feels excessive (this does not mean I'll be shaving it off and sending it to the Gulf Coast. Fall comes quickly around here).
Secondly, whatever is the Gulf Coast going to do with all of this hair? (I just googled Gulf Coast oil spill + hair donations, so now I know. Sometimes google just takes the fun out of imagining). It is being used for its ability to trap oil (which, by the way, was my #1 theory before googling). Let's think carefully about this one before we jump in, shall we? I'm not sure it's a good idea to throw "excess" OR "excessive" hair into an already gruesome mess. Think bathroom sink, but on a massive scale. Who wants to clean THAT one up?
Maybe it's an ingenious idea. Maybe it's "hair-brained." But until I see results, I'm holding on to my hair, excessive or not.