Again, the advantages of disk has nothing to do with brake force. That said...
I honestly don't mean any disrespect here - I've read Many of your posts in the past and I know you have lots of knowledge, but on this subject I think you could continue to learn about the new aspect of it. If nothing else, disk brakes seriously do offer better modulation. The system lends itself to it from a mechanical aspect. Disk brakes just aren't as grabby, so you can adjust the braking force more subtly. As for your hydraulic being very on/off, I'd recommend somehow adjusting them or perhaps it's a poorly designed set. I'm not sure. They would be very powerful, so you can't go just grabbing and squeezing the lever like you have to on non-disk brakes, so keep that in mind, but they should offer a very wide range of braking force. Also, that you said all of your brakes are at wheel lock by the half travel point of the lever gives an indication of how you set your brakes up. You probably also have fairly strong hands and use more hand strength vs. mechanical leverage to stop when compared to others. Not that there's anything wrong with that, but it's opposite of the idea behind disk brakes. It's like driving a modern car vs. an old classic with no power brakes. If you grab a hand full of disk brake like you would regular brakes, you are going to go straight from no brakes to wheel lock. Just like if you're used to driving a car without power brakes and then hop in a 2014 Honda, you're going to lock the wheels and come to a screeching halt the first time you try to stop. If you look up Sheldon Brown's article on "the geometry of cantilever brakes" and scroll to the "feel vs. function" section, that will perhaps better explain what I'm saying in terms of why the way you use brakes is so different from the idea behind disk brakes and why you aren't seeing their modulation benefits.