The Abandonment of the Gladius for the Spatha - Why?

[TraderTrey9785]

Looking at pictures and reproductions of most spathas, they're nothing more than a gladius with a longer blade. However, they do tend to resemble early versions of the famed Norman Sword carried after 1000AD. Could it be possible that new developments in the defenses of Rome's enemies required a blade that was longer and heavier to deliver a stronger cut or slash into an opponent? The short sword was designed to be a thrusting sword, even with its restricted length; however, a spatha clearly looks like it was intended for hacking away at an opponent, the primary reason it was carried by the cavalry. Maybe the infantry units realized that instead of trying to get in close and stab their opponent they were much better off to just slash away and hope that the weight of the blade would be enough to incapacitate their opponent?

Just a thought, I'm no sword expert, but I think the longer reach and heavier cut was a must have for the Romans....

-Trey