I've done the modern "tactical" knife thing. Big knives like the Military, BM710/806, large Sebenza, Severtech, ZT, etc. I found that I don't need that much knife. I only have a handful of modern folders left, and they have thin blades, thin bodies, and even though I carry them, it's usually the traditional knife in my pocket that I prefer to actually use.
Here are my personal reasons for preferring a traditional knife over a modern "tactical" one:
Aesthetics. I like jigged bone, burnt stag, the natural grain of wood, and the simplicity of yellow delrin. I like G-10 and Carbon fiber too, but there's much more charm and class in the traditional materials.
Tradition. I'm relatively young, but I like carrying an old (or old-style) knife because I feel it connects me to the older (and disappearing) generations.
Thinner blades. I don't need to chop a limb, baton wood, or carve up a car door, so a thick "folding prybar" knife is overkill. Thinner blades suit my needs better.
More blades, different edges. A 3½" stockman has nearly 6" of cutting edge packed in that small frame. Main blade for general use, the sheepsfoot for opening packaging, and the pen/spay for detailed work. Or you can choose any multi-blade knife that suits your needs. You can put different edges on blades; fine for delicate jobs, coarse for rough jobs. You can choose redundant blades and have a second blade ready if the first goes dull. The choices and possibilities are almost endless.
They don't scare people. Even though I live in Arizona, where you can carry and own pretty much any "weapon" you want (except nunchucks), I'm still not all that fond of whipping out a big honkin' modern knife to do something simple like opening a box cleaning a fingernail.
They're more honest. As I just said, I feel foolish pulling out a large "tactical" folder to do something that I can do with a small slipjoint. I don't need a 4" blade to trim a loose piece of thread or cut out a coupon. I don't need the strongest lock in the industry - or any lock at all really.
I still understand the convenience of a knife that can easily be opened with one hand and can lock, which is why I still carry them as well. There may come a situation where digging into the bottom of my pocket for a knife that requires 2 hands to open wouldn't be an option, but the quickly accessible and opening knife clipped to my pocket might be a necessity. But for the most part, the knife I go to for daily use is the multi-blade traditional slipjoint.