Me too.
For almost 35 years (my 40th anniversary is next month) I did whatever was needed to get the job done. I was a "working" manager, as were all the other managers and supervisors on the production floor. A new regime (GM and operations manger) came in and suddenly over the last 5 years that work ethic was deemd "antiquated" and not suitable for today's "lean" techniques. We were all told our "tribal knowledge" was worthless. Well, in 6 months or so, the operation will likely be shuttered for good. All that business school mentality ruined what was once a thriving leader in our industry.
My last 3 or 4 reviews were the worst I've ever had. After the last one, I went to HR to complain and asked how I (along with the "dinosaurs") managed to last so long? The HR manager, being a long timer herself, agreed with me in principal but told me the best course of action was to "play the game" for as long as I could because they weren't going to change their mindset. It's like the sweat equity I put in over the years was all for naught.
The saddest thing about the whole situation is we'll all be out of jobs but the management that drove us into the ground will still be employed (transfers to other locations, etc).