I asked them directly. There is no direct reason whatsoever. They just rushed it and fucked up. Nobody ever thought about FLOSS besides vaguely excluding it in the "noncommercial" way.
There were more landmines in the original draft. Like the requirement for any known-vulnerable device not be put on the market. Well guess what? All those phones and laptops sitting on the shelves are having exploits discovered every month.
Red Hat chimed in; apparently they have potential vulnerabilities on containers they publish sometimes in 15 minutes. Potential. How exactly are they supposed to act?
The legislation just plain sucked and now it's being "fixed" behind closed doors.