What would you choose? All Windows or mixed Windows/Linux

I ask because I’m being pressured by my manager to agree that we should revise our network infrastructure to completely eliminate any Linux servers. this would then leave only Windows machines which would then be ‘easier to manage’ and be more ‘cost effective’ in IT Support terms.

My colleague and I have brought up the the fact that any system where security can be compromised across the board in minutes is a bad idea.

I guess the corollary to this is the question of whether it’s worth sticking it out in a job with a stubborn manager.