Wondering why they haven't licensed it under GPL3.0 so at least other countries would have to also open source their apps if they reused the code. Also if some company reused the code to implement some malicious verifier that do tracking it would be easier to find out.
You want to err on the side of letting proprietary closed-source code bases (think "electronic health record" systems) adopt the reference implementation, even if they don't give back.
Otherwise the proprietary folks will come up with a competing implementation that meets their non-technical (licensing) requirements.
