[Wowfunhappy]

Playing devil's advocate: if I did in fact grab one of my kitchen knives to defend myself against a violent intruder into my kitchen, I wouldn't expect to be banned from buying kitchen knives.

I'm not sure this is still a useful analogy, though...

[dwattttt]

And if you grabbed the knife and went on a violent spree, I'd absolutely expect the knife manufacturer to refuse to sell to you anymore.

The knife manufacturer isn't obligated to sell to you in either case, I'd expect them not to cut ties with you in the self defence scenario. But it is their choice.

[zephen]

The knife manufacturer would be more than happy to continue to sell to you, except for that minor little detail that you're in jail.

[Loughla]

If I shoot someone, something that is explicitly warned against in firearm safety materials that come with every purchase of a new firearm, I am no longer allowed to purchase any more firearms.

[SauntSolaire]

There are many situations in which you can shoot someone and still be allowed to buy a gun.

Also, in the cases you can't, it's generally the government stopping you, not the gun companies.

[Wowfunhappy]

That's for a different reason though--you broke the law.

[moron4hire]

The specific shape of a kitchen knife would make it a particularly poor fighting knife, and knives in general are bad for self defense, due to the potential for it to be turned against the user. So, there is a good argument that such a suggestion is really in the user's best interest rather than a cynical play for the manufacturer to limit liability.