I think for me it is simply because knives are my passion, multitools are not. I carry a Swiss Card in my wallet but I rarely use anything other than the scissors.
While very useful for some folks, a SAK or other multitool just doesn't have the same appeal to me as a good old fashioned pocketknife.
That sums up where I'm coming from.
Most of the time I carried a sak, I used the knife blade more than the tools. If I need a screw driver, the Sear's 4-way keychain screw driver works for me. I learned how to open a beer without a dedicated opener tool. With a P-38 in my wallet with the Sears screw driver, I'm all set to handle most of what my sak did. I do carry a little sak classic on my keyring, and that packs a lot of utility in a very small package. After a lot of years, I just took a hard look at what I used most, and a regular pocket knife works best for me. With a peanut in my pocket and the Sears keychain screw driver and P-38 in the zip compartment of my wallet, there's little I can do that a sak soldier can do for me better. But the knife I carry has better steel than the sak knife blade.
Multible blades instead of tools for me is a good thing. A two bladed pocket knife gives me an extra blade to use on the rough dirty jobs that I know will dull up the main blade. Two blades, two different edges to use. Two different blade shapes and point styles. When I carried a stockman, I had a use for each of the three blades.
I am a product of the age I grew up in. I don't like the plier type multitools, never had one, and I doubt I'd try one at this stage of my life. I'm too much of a die hard traditionalist. And sak's just don't have the feel, or soul of a nice bone handle pocket knife. I must not be that alone, as the tool knives are not new. They had tool knives way back in the 1800's. And in the early 1900's with the advent of car's and electricity, they had a zillion pocket knives with screw drivers, and even open end wrenches that fit a wide variety of nuts. But even with the modern age, they did not over take the plain old pocket knife. Not until well after WW2 did the sak's become popular in this country. It wasn't until the 1980's that we got the Leatherman.
I find that the older I get, the more I like to get back to basics. And I want some style and beauty in the things I use. Blued steel guns with nice walnut stocks. No plastic need apply. Knives with natural handle scales like stag or jigged bone, or nice wood. I've only got so many heartbeats left, and I don't want to waste any on ugly stuff with no grace.
Carl.