I think it's simple, people catch more fish constantly. There is something to be said about the feel of the fish striking the lure though.
Let's look at the costs. You need poles either way, so no difference there. In line boards can be very expensive, but it's basically a one time cost. Lures: now here is where you can spend some money. You don't have to, but it's a slippery slope. I don't have a ton of lures, but I do have a few. The thing is a guy doesn't need a ton of them. There are about ten different ones that I use to catch all the walleyes I get and like most I get quite a few. So you already have a boat, so money isn't an issue. If people spend just a little more, they can catch fish like the pros, or they can go around looking for fish, wishing they were catching them.