> Of course, all we have are toy models and speculation
These two statements could be construed to be in conflict, especially as I haven't the faintest idea what naive discretizations of stable ODE's is, and Google isn't of much assistance in providing an explanation that I can digest.
An explanation of ODEs and instability (some math background is obviously required): https://en.wikipedia.org/wiki/Stiff_equation
To me the idea of slowing things down sounds vaguely sensible, but I also know that I don't know enough to really judge. So it sounds like no one else really knows either, but the entrenched players like things the way they are, which makes sense, because the ones who have the money to be at the table running things are probably also the ones who have the money to throw at HFT and come out ahead.
I.e., if you ask me about the stock market, a flight control system, an electric circuit, a biological system and a computer network, I'll tell you that continuity gives you a better shot at stability than discretization in most of them.
I.e., if you don't know what you are talking about, lean towards continuity. If you do understand things, then explain the mechanics and back it up with empirics.