Not working on ads isn't a conflict of interest — there's no metaphorical paycheck for dodging Google. As you point out, it could predict more ignorance, but it

Not working on ads isn't a conflict of interest — there's no metaphorical paycheck for dodging Google. As you point out, it could predict more ignorance, but it doesn't predict financial incentives flowing to their direction. Also, would you morally expect your doctor to disclose that they're on the payroll of the company that develops the medications you've been prescribed to take? Regardless of the answer, disclosure here isn't about whether or not a doctor is capable of their own opinion, or whether or not they are speaking in any official capacity for other companies. Ethical appearance is part of professional ethics. Similarly, it doesn't matter if a judge is capable of independent opinion while having financial interests tied to the cases they preside over. The mere appearance of financial entanglement can stink up professional credibility. It would also be quite silly for a judge to respond with, "But I've only recently been receiving paychecks. I hardly know anyone at the company."