Other SBC makers don't have an issue offering full schematics, yet, due to their smaller size, have relatively more to lose from being cloned. Moreover, I hope nobody believes that a lack of full schematics is going to stop people from making clones. Schematics can be reversed with not too much effort. Due to their large audience and brand recognition, rpi actually has less to fear from clones than smaller SBC vendors.
If anything, it seems like they've judged that their large size and brand recognition is something that they can coast on to avoid having to offer what other SBC vendors do.
I'm not complaining about rpi existing, I'm pointing out that what they offer is in certain aspects inferior to the offerings of smaller SBC vendors, which is actually surprising, given that their large size should make them much better resourced to match or exceed the offerings of those vendors. This causes me to question whether these values are actually a priority at all, even if they claim so.