Why would low lift head flow hurt power?

What I'm kind of getting is good low flow numbers generally comes at the expense of mid-higher lift numbers ? So it's not that higher low flow numbers are bad in themselves but your generally given up better mid-higher lift numbers to get them?
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.