I should not have to manually clear the history. It should be possible to disable the algorithms without losing your history. The same problem exists for search where they don't even use your account but instead rely on 'unique fingerprint' provided by your browser.
What is you concern about losing the youtube history, I don't think I have ever used it once. Yes browser fingerprinting is a different issue, if you are really concerned there then I suggest EFF's Privacy Badger.