"debugger vendors in 2047 distributed numbered copies only, and only to officially licensed and bonded programmers." - Richard Stallman, The Right to Read, 1997
People will be running pirated debugger copies if that comes to shove
99.9% of people DNGAF about OSS. They do care about doing what they need on their phone without malware/bloatware/nagware
Also publishing and development are separate activities
It is surely possible if only because the general population is not interested in infosec.
On the gripping hand,firmware writing practices being that they are; it is impossible to produce an uncrackable phone.