> that it takes following the... (charitably) uncommon view that Fëanor was a "good guy" in spite of being a psychopathic thieving mass murderer to excuse the actions of Palantir (the company) should be an indicator that they're Bad, Actually.

While I agree with your assessment of Fëanor I don't think anything in Tolkien's texts indicate that there were nefarious intents for palantiri creation.