Meh. Not sure why knife dealers would be assumed to be more moral than firearms dealers. See, e.g. Delana v. CED Sales (Missouri)
> the bad PR (see the "found out" and "direct to consumer" part) would make you a hugely unprofitable customer.
That... Doesn't happen.
Boycotts by people who weren't going to buy your product anyway are immaterial to business. The inevitable lawsuits are costly, but are generally thought of as good publicity, because they keep the business name in the news.
People who buy luxury kitchen knives are exactly the type of people who would choose not to buy a product because it is associated with crime.
People who buy (and make) firearms are... pretty close to the exact opposite.