That’s how it has been in the US. Now, though, if you already have a passport, you can renew online and take the picture yourself, and get it mailed directly to you.
The thing that makes getting a passport slightly tricky to begin with in some circumstances is needing proper ID. In the US, there’s no generalized law saying that you have to have certain forms of ID. Most people use drivers licenses as ID, but obviously not everyone has one (by choice or as a consequence of drunk driving). There are a lot of people without ID, and there are ways to get ID, but they can be difficult for people without resources. A birth certificate is hard to get if you don’t have one already, especially if you don’t know where you were born.