Companies just are not spending those kinds of dollars on that type of marketing any longer. WIth the shift of ecommerce, spending money on someone creating a logo that is enduring is more valuable. I work for a company that simply only creates swag for two public events a year. We sell through it uber fast, but our owner doesn't want to sit on stuff that is likely going to be given away, when he can spend those marketing dollars on SEO, quality graphics and website utilization.
There are a few overland product companies who sell patches. At an uber premium. People buy them.
I personally would rather spend the money on parts and travel and NEVER would ask for something free. But, thats just me.