All will eventually have to learn how to use a knife some day. The only question is when is the good time to start teaching.
Not married and no girlfriend yet, but when I finally do so and have children one day my entire collection is going to get locked up in the safe (they sit in my drawers now). The kids won't be allowed to touch any knife, not even the kitchen knives, until they are at least 7, and the only exception I will make is that for table knives (with rounded tips to boot).
Once they reach 7 I'll let the wife determine whether she's comfortable with teaching and letting them use the kitchen knives. As for folding knives or utility knives or <insert other typical EDC knife type here>, the plan is to casually play with a couple of them in front of the kids to gauge their interest. If they see it as a new toy, then they are not ready and back to the safe it goes.