[doque]

I agree. There are plenty of freedoms built into the REST way that enable you to create more or less detailed responses.

  "I don’t care. Trees are recognized by their own fruits.
   What took me a few hours of coding and worked very robustly, with simple RPC, now takes weeks..."

Weeks? For a REST API? No, I don't think so. REST gives you the tools to be pragmatic and quick, so use them.