I defend the co-worker in this case because not everyone is into knives. Before I became interested in knives, I had a cheap Chinese knife that had a plastic frame, spray-painted silver, and a polished 3-inch blade that served my needs quite well. Its edge-holding retention wasn't great, but it opened packages at work that came taped up, cut cord and generally did everything I needed to do. As I used it, paint would flake off the knife's frame, but I had a cheap Lansky 20-degree sharpener I kept in the closet and used to keep the knife wicked sharp. I still have it in a box somewhere and occasionally carry it for old time's sake.
My point is, a knife is a tool. It can be used for office use, opening boxes, cutting thread, cardboard and even cutting food. And whether it's a cheap Chinese liner-lock or a Sebenza, knives do the same thing. I have an old Chinese knock-off of a S&W Homeland Security made by Frost. Cost me $13 and I only wish I had bought several. The finish is spray paint on the blade, full tang, a surprisingly sharp blade and the knife would be impervious to brutal batoning. It also is easy to sharpen, can and has been used to clear ice away from the cars in the winter. It's the quintessential "crummy knife" of the age and as I said, it's a knock off of a Smith & Wesson, no less! But in a bug out bag, it wouldn't be the last knife I chose. It can be sharpened on a creek stone and would last a lifetime.
So as far as crummy knives go, even if you gave this guy a nice knife to replace the one he "fixed," what would it avail him? If what he has does the job, why does he need a replacement? He clearly doesn't appreciate knives -- probably doesn't have a box full of them under the bed like many of us do. So why worry? If it falls apart, he'll either fix it again or get a new one. But even if he gets a Spyderco Military or Endura, he won't most likely won't view it as anything more than a tool, like a screwdriver. So how does one change that?? Or want to??
The Frost (top) is cheap but functional. The Maxam (bottom), another cheapie, has a 5-inch blade, and was another knife that I used frequently at work. Both now ride in my car trunk. In a way, if they hadn't existed, I might have never have gotten into better knives.