There is a way...
Analyze what everyone needs and wants out of the network and office system. Determine if it is drive space, server capacity (CPU cycles), etc. Take your findings, and determine what can be changed in the office to effectively reduce the clutter, the over head, and of course, the cost. Generate charts that show how moving to the new system would save the company not only time, but energy maintaining the network, backing things up, and be an asset to the company.
Now present these finding in a clear, non-judgmental way to the upper management who are involved in the decision making process of this area. Show them how they will SAVE MONEY. Maybe they will listen to you, maybe you'll get assigned the ask of implementing the project. Maybe you'll launch your new career. Maybe you'll be unemployed, but happy.
I would totally avoid mentioning anything about Macs unless you can prove it will be a big asset to the firm.