To say it's a privacy nightmare in the context of a Google thread is just not accurate. If they associated search queries with your account then they'd be breaking their own privacy policy and opening themselves up to lawsuits.
No it's not horrible for privacy it's literally just for billing which payment can be made anonymously too. They don't even verify the email address you use. So much misinformation in this thread. Go Google your info before you present it as fact.