How can a speed impeller affect the AP?

OK, maybe the AP has algorithms that use speed as a component, but my speed transducer is normally pulled out (dummy plug in use) and the AP works fine. That said, my stuff is Raymarine and I'm quite sure that if I disconnected the NMEA and SeaTalk instrument bus from the AP and restart, I could still use it. I'd just steer by hand until the boat is pointing where I want and set the AP to track "present" heading by pushing the "AUTO" button on the control head, then it would continue to follow that heading until I make adjustments with the + and - degree keys or disconnect it with "STANDBY'.

Putting that aside, I do like having the wind meter interfaced to the AP. It allows me to set the AP to track AWA.