You are correct. As long as you do not remove it from your account, ever.I always though signed into iCloud and find my phone turned on was pretty much making the phone a paper weight when stolen, even DFU restore would make it activation locked without the apple id password.
Thieves sell the phone for $50US or so to a 'holder'. They hold the phone for 1 or 2 years, waiting for the user to remove it from their iCloud account at which point they DFU restore it and sell if for the current rate. Very simplified explanation.