[fullshark]

Do you think these companies would keep giving PBS money if they stopped reporting who was giving it before/after each show?

Also your claim isn't even true, I recall an ad for a European Boat Touring company before Rick Steve's Europe for example. The ad was clearly "this company sells this product."

It's all just another form of lifestyle ad / virtue signaling. "We support PBS and the things you care about, support us too."