How to deal with authority bias?
I bet you're not the only one with such experiences :)

One possible approach today (which wasn't available in the early DevOps days) is to counter-argument with the many research-based publications from industry-recognized influencers. Like Accelerate or 2017 State of DevOps Report to name a few.

Another approach could be to propose and implement DevOps-based pilot projects to actually measure and compare performance parameters against the existing silo'd solutions. This could be tricky, though, as those influencers could insist on requirements cornering the pilot projects. For example insisting on individual/small team development speed which could be an obstacle for optimizing and speeding up the overall larger/entire project team's development.