A good knife is sold by the name of it's designer, not a celebrity.
Well, yes and no. I have many knives, and unless their name is somewhere on the blade (like Kershaw and CRKT like to do) I couldn't tell you who designed them, only what company they're from. I buy instead from reputable companies, comfortable that the product should be well made, and that the company will stand behind the product if I happen to get a lemon.
As for the original question asked, I think most of the celebrity endorsement is laughable. An example for me is R. Lee Ermey. I mean, gotta give the guy credit for having milked eleven years of military service into a saleable persona, sure. But the whole Gunny thing that SOG's beaten to death is just clownshoes at this point. Similarly, the Bear Grylls thing. I mean, Gerber has an entire line with that guy's name on it now. Canteens, a "survival belt", and so on. What real survivalist would wear ANY of that trash? You damn sure know BG isn't.
I don't know why companies even still bother with celebrity endorsements anymore. A thinking man understands that a celebrity endorsement means "Stand here, hold this product and read from this ad copy that was carefully prepared by our marketing team. You can collect your check on the way out." and nothing more. Bear Grylls isn't hacking his way through a rain forest with a Gerber Bear Grylls Parang, we all know that. I'm pretty sure Les Stroud isn't using that cheap Chinese Camillus "arctic" knife. So, in my mind, celebrity endorsements could
actually be taken as a sign that the company is trying to move a low-to-middling quality product and charging more than it should cost, because they've slapped a celebrity's name on it and hope that people will buy it based on that fact.