Programmers often discover solutions while explaining a problem to someone else, even to people with no programming knowledge. Describing the code, and comparing to what it actually does, exposes inconsistencies. Explaining a subject also forces the programmer to look at it from new perspectives and can provide a deeper understanding.
Same, my work laptop is locked down hard but I have admin access to some production servers.
I guess it comes down to they trust me, but they don’t trust the networks around me.