Which is to say, beta readers are great, and y’all should totally have them. But editors do something totally different. And “totally different” does not, as it turns out, entail tearing you and your work to shreds and making you feel like shit. No one “loves” edit letters because edit letters mean more work, often on something you just want to be over with already urrgh gods I’ve read it a thousand times why are you making me do this again? But the end result of an edit letter should be a manuscript you think is stronger than the one you had before you went into the process.
KJ Charles was an editor before she was an author, and here she lays down how to spot a bad editor (or “editor”, as the case may be). This includes a Handy List for authors, with the #1 point being about ensuring you have a clause in your contract specifying your work will receive professional editing, with the emphasis on “professional”, because “professional editor” is, in fact, a skilled career with associated tertiary and professional qualifications, and should you suspect the editor that’s been assigned to you is, in fact, an “editor” rather than an editor, well then that’s breach of contract with the publisher.
Basically, you’re better to self-publish–or to not publish at all–than to go down swinging with bad edits.