Ps3 Audio Receiver Hdmi Onkyo HT-s5100 And PS3 Audio Via HDMI HELP!?

Onkyo HT-s5100 and PS3 audio via HDMI HELP!? - ps3 audio receiver hdmi

Basically ... Look over my Onkyo manual says:

Step 1: Connect your compatible TV's with HDMI AV Receiver HDMI OUT.
Step 2: Connect the player compatible with HDMI-HDMI to the amp in 1, 2 or 3 jack.
Step 3: Connect the player to an HDMI-compatible analog and / or digital audio input on your AV receiver.
Step 4: Arrange the HDMI IN.

What I have trouble understanding is the following:

If I understand the two HDMI outputs in the form of high-quality video and audio. If so, why not add a second component cables for my system (analog or digital running) for this connection? It is the purpose of the 3 HDMI "in" on the back of the Onkyo receiver made simple "pass" video on TV? It makes no sense to me ... that only the videos do not use high-quality audio ... mainly because it is a 7-speaker surround sound system 7.1.

Thank you!