@oscarberg writes "Adoption of new practices and systems has always been about the people, but making adoption optional makes it even more so".
One common pattern of adopting an innovation (whether technology or practice) is when people just go through the motions for the sake of compliance - superficial adoption without real commitment.
So real (committed, authentic) adoption is always optional. You can force people to adopt something superficially, but enthusiasm and commitment can never be mandatory.
This is why, in the context of change management, the concept of "resistance" is more complicated than people usually admit. Lack of resistance isn't necessarily a good sign; it may merely indicate that people have worked out how to comply superficially with the innovation without actually making any meaningful change. Or even that they have seen a way to divert the innovation to their own selfish advantage. Whereas real commitment is often preceded by a serious engagement with the substance of the innovation, which over-impatient managers may experience as resistance.