Well, first off, most people these days don't carry a knife.
Look where you are, you're on a knife forum. People here are the 1% or less of society that goes obsessive over knives. We're the vast minority of the populace at large. Even backpackers din't carry much beyond a little Vicorinox classic or Leatherman squirt.
As for small mulitools with a knife blade, it makes very good sense. They give you a knife blade very capable of cutting open a UPS package, cutting some twine or a piece of rope, plastic blister packaging. You may carry a neck knife, but I'll bet you 500 bucks that you can line up the next hundred people you pass on the street and never find a neck knife or any other dedicated knife. Neck knives and such are the relm of the dedicated knife nut, and businesses can't stay in business catering to the 1% of the populace.
Victorinox like Leatherman, has retained it's spot as the worlds largest knife company by making knives that appeal to the masses. LIke Tim Leatherman, they sell tot he everyman. The fact that the mulitool makers, who do tons of market surveys to gauge the public, put the knife blade on the multitools, tells us that they are on the right track for the sales to the human race that are not dedicated knife nuts. And even though I am a knife nut, I find the knife blade on my leathermans a useful tool.