I've wondered the same thing but haven't come to a conclusion about it. I'm skeptical of any improvements the ortholinear layout would bring to be honest. If you are using a keyboard enough, the particular locations of any given key will be firmly in your muscle memory. However, perhaps it makes sense ergonomically for a split keyboard like this, since your hands are pretty much exactly perpendicular to the horizontal direction of the keys, so finger extension direction would indicate an ortholinear layout being ideal.