i got
this set of actual nutdrivers for $20 a few years ago. Right now, it's $30, which is only slightly more, so why
not have a set of nutdrivers?
if you've never worked out of a tool bag or belt, there are a lot of tools that won't make sense to you. you end up buying tools like double-open ended wrenches and multi-bit screwdrivers to save space and tools like nutdrivers to save time and fumbling. I remember when i did wiring, i had two separate punchdown tools so i could switch between 66 and 110 blocks without having to switch the blade (i spent $50 for the second one just for that!). If it makes you more efficient and makes the job more pleasant, it's worth it.
Also, nutdrivers usually have hollow shafts (or at least partially hollow like that craftsman set) so you can run a nut up or down a shank, which is what makes them nutdrivers and not boltdrivers. A spinner handle is not functionally equivalent in this case. My klein set also has little magnets inside to hold the nut (without interfering with the hollow shaft), which i find very handy as well. Every nutdriver thread, there's always one guy who points out that you can buy a spinner handle instead. Most of us are aware that spinner handles exist, but we still have nutdrivers because they're really not the same thing.