Why would low lift head flow hurt power?

Generally speaking we could just make the port bigger and then all those numbers would be bigger including the low lift we would just have kind of ..a lower velocity thing going on.... oh wait, that's the hemi. Lol no wonder they went with two intake valves on the new Hemi

Think of velocity also as a flow curve..it is.. every lift increment, how much is gained ...and when that starts to slow what it does to power/rpm.

Or what happens when the velocity is too high.