I totally see your point. Though i would argue, that a small business owner SHOULD be thinking about this.
I am just saying supply chain is more difficult than this. If a business creates a precedent that all knives will have plastic tips, then someone has to spend their time making sure that it is always available, and on hand. The physical cost of the thing, does not necessarily translate to making business sense.
Obviously as a knife enthusiast at this forum, I think it is inexcusable for a product to come damaged, but from a procurement point of view, and a COGS view i do understanding that sometimes it is more cost effective for a customer to end up unhappy, and not repeat business than to put in place a "fix" that will not cause an issue to happen again.
I would ask how many knives to they sell a year, and how many people complain about broken tips. There is always a cost/benefit