To be blunt with an approach like that its a good job you aren't a manager. But then I wish a lot of managers in Royal Mail had a least a modicum of training in personal skills.
I have been one (not in RM) and there are some simple rules to go by.
1. Try to lead your workers into change, don't force them.
2. Listen to your workers, they usually know the coal face conditions better than you do.
3. Try to keep your workers happy as a happy workforce is more productive.
4. Train your managers and workers properly - it's cheaper in the long run.
5. Try not to lose long serving employees their knowledge is hard earned and not easily replaced.
6. Workers are a not a resource to be discarded with an "if you don't like it leave", they are an asset that if treated well, generally reflect well on the brand.
Sadly RM don't do any of these, and evidence seems to suggest you wouldn't on at least one of these.
As an aside I always thought if you don't like it leave is a pessimistic approach. Why not, If you don't like it, stay and make it better. We won't stop all changes, but we can at least make them better and more workable.