Using f22 as the starter, the first combo you listed does 310. The second does 298. Clean cuts BnB for a bar does 293, so basically speed demon does about .5%- 2% more damage per BnB is what I’m seeing. I don’t think that small damage increase + a bit more corner carry is enough to outweigh the benefits of having a high damaging restand ender that can be used to end every combo. I see that using the hook grab to extend AAs/KB combos adds significant damage, like 8-10%, that’s pretty awesome, but his launching KBs already do huge damage. I feel like using the bar to add more is situational to close out a round/gain a lifelead if possible, but not something you’re gonna want to do every time.
I also totally forgot to mention the KB on low hook, which is 100% viable and can easily make up for the small amount of damage lost by not having spinner/hook grab. Spinner doesn’t seem like that great of a move to me, it’s unsafe regardless of if you amp it or not, and in the corner you don’t really need it to launch because you can just throw a meterless saw after any starter and combo that way. The only good thing about it is a little extra corner carry.
Using the Extended Hook restand means sacrificing damage, the frame advantage is minimal, and even with the Low Hook Grab, Kabal's mix-up potential isn't good enough to take full advantage of it. And again, constant restands means the opponent will almost always Breakaway once you finally land that launching Krushing Blow or wake-up/FB u2.
Finally, to restand a cornered opponent with the EH, you have to sacrifice the corner or a lot of damage unless you use the Amp Buzzsaw, which only combos from 22 and b12. By contrast, Hook Grab lets you switch sides to restand with Gas Blast, which gives better frame advantage (and either even more frame advantage or the heal/DoT/no jumping gas cloud if you spend your second offensive bar to Amp it).
I don't think Kabal's Krushing Blow combos (or, indeed, any of his combos) are all that damaging without the Hook Grab. You ALWAYS want to use the offensive bar for the Hook Grab, because he doesn't need the bar for much else (apart from making his air Buzzsaw even safer).
The Low Hook KB is only really effective against players who don't know it exists. It won't trigger in 50/50 situations (i.e. after b1, f22 or f4), and there is no reason for the opponent to block high after anything else. Of course you can land it on occasion (mixing in short hop overheads, etc.), but the risk/reward ratio just isn't in Kabal's favour most of the time. If the KB condition were to change to "land it three times raw" or "land it five times, comboed or not", it might be a different story.
Like I said, Low Spinner is marginally useful, but at least it has its uses, unlike, you know, Nomad Spin.... ^_^
In short: without Hook Grab, Kabal's damage is sub-par given how hard it is to open people up.
With Hook Grab, he becomes a threat at mid-screen and an outright menace in the corner. I used to be a Clean Cut main, and I still miss the Low Hook and its cool-looking KB, but SD's damage and corner game are just too good to pass up.