I was recently in a position to see how another writer I know handled their first round of content edits, and it went badly. The editor requested several changed in the manuscript, and offered suggestions on how to make the changes, but was clear that the changes needed to be made in the writer’s own words. The suggestions were pretty basic. Move this sentence here, incorporate action, add description. Very basic edits that. To my surprise the writer was offended. The writer wrote comments in the margins questioning the editors experience, taste, and knowledge of the market. Unsurprisingly, the writer’s contract was suspended.
Content edits aren’t like a critique from a writers group. You can disagree here and there and discuss it, but to say no to everything is just immature. Once your book is under contract, pretty much what they say goes. That doesn’t mean you lose creative control, but if you can’t handle constructive criticism, than you’re in the wrong business.