Your right, it is possible to hit differnent muscles at different angles. Now why anyone would want to do this is beyond me though.
Here is another myth.
1. You can get a larger upper chest by doing inclines over flat db presses.
2. You have to do inclines and declines to balance your chest.
3. Flyes target the inner chest (LMAO).
4. Inclines serve a purpose.
5. You can change the shape of a muscle without surgery.