Because this allows you to keep the halves further apart, which is considered more ergonomical.
Typically, each half can, in fact, be used independently (they each have their own microcontroller).
Also, for some folks, videos are a massive pain to watch due to accessibility issues. I’m medium lazy non-mongrel but I happen to have shit hearing, so fuck me, right?
That looks absolutely stunning, great job! Really futuristic and clean!
Or, maybe, not go out of my way to fit my way of working to someone else’s notice of how I should be doing things? If A works and B doesn’t, unless I put in a lot of effort… Why exactly would I?
Because then things like holding shift on one half and a letter on the other wouldn’t work.