If it was a salaried job you would have to sign a Non-Disclosure, assign all intellectual property rights to Apple, ensure that you have good work attendance, be responsive to what your manager tells you to do, etc, etc...
I'm sure there are a lot of security researchers who would like to dabble in dozens of companies products, without being told what they had to do every day, yet still be compensated.
I'm sure there are a lot of security researchers who would like to dabble in dozens of companies products, without being told what they had to do every day, yet still be compensated.