"Uncatchable" rule???

Can someone please explain to me the whole concept behind the "Uncatchable pass" rule? I don't understand the point of this rule?

So if the QB makes a bad pass and the defender commits a penalty it does not matter? Why? It is still a penalty no? If a lineman holds on a play where the defender still makes a tackle or sack, is it not still a penalty? I don't understand the point of this rule. It makes no sense to me. A penalty is a penalty no matter how bad of a pass it is. The receiver was interfered with which would stop his ability to make a catch on any pass so why does it matter if it was "Uncatchable"?

I should say that I am an LSU fan and am writing this in reference to the play yesterday where the refs picked up a flag for PI when Lee threw it out of bounds. And i remember a few years back when LSU lost to Auburn when they picked up a PI flag in the end zone when Early Doucet was held on a fourth down i believe. This rule to me seems like nonsense. And I know there are other teams and schools that this rule has affected.

Can someone explain the point of this rule to me? :idunno: