Of course I judge books by their covers. "Cook book" is likely about cooking. "Tax filing for dummies" is probably about tax filing. I judge chairs by their covers, too: If a chair is covered in barbed wire, it's probably not a very good sitting chair, if its cover is leather and plush, it's probably more comfy.

Every day humans judge everything by their covers, to 99.99999999% success. I don't see why people think this is weird. If a woman is androphobic, she likely didn't even go up and ask if any given man identified as female before getting nervous, let alone their life story! And that's fine. It's how the world functions on a day to day level.