There are many apps stuck with a 17+ rating due to the app being able to access content from the web which may or may not be kid-safe. It's a policy which is paranoid and inconsistently applied, but it's not entirely arbitrary.

I get that...what irritates me is they don't do the same with Safari. With this logic, one could complain that the alphabet isn't kid safe because you can make naughty words out of it, or that a clock app promotes pot use because it reads 4:20 twice a day. A 17+ rating applied on such general grounds really creates a false impression about the products it's applied to, suggesting they are somehow more likely to expose the user to objectionable content and thus hurting sales.