Why would low lift head flow hurt power?

Original question why would more low lift flow hurt power, .100 - .200 brought up by the guy at trick flow.

What I got so far is .100-.200 is where both valves are open during overlap and don't want the intake easily overcome to reversion.

Plus, why do you want the valve hanging around those low lift? It makes no sense.

No matter how great your flow is at .200 it better damn well be better at .500 and .600 and .700. Why leave the valve there.

Valve speed is horsepower if you control the valve train.