Great question and I can't answer it other than I like the rods I use for them. They are as you describe, and my crankbait rods are mostly inexpensive composite fiberglass, while I use a graphite spinnerbait rod for jerkbaits, which is stiffer anyway due to the difference in materials in the rods.
I'll toss some very light lures, both types sometimes on ultralight spinning gear and treat them both the same, except different cadence and rod manipulation with the retrieves. Although I may not be specifically targeting bass when I fish with them, juts anything that might hit the lures.
Technique is different otherwise, as I often just cast & crank a crankbait, allowing it them to bump & bounce off whatever is there, but get much more erratic with jerkbaits with stops & starts and rod manipulation. Sometimes fish them on the surface too. There was a time I fished them both the same way, before they called them jerkbaits. Used to just call them "minnow" lures, such as the original Rebel Minnows or Rapala balsa minnow. Didn't know any better.
I also toss big 7" jerkbaits for Stripers, and fish them the same ways as I do for bass, and with a stiffer rod because the lures are heavier, as are the size of the trebles. Just what I've gotten used to doing.
Maybe someone with more technical knowledge of rod design will post something because I would also like to know.