I already answered that
Please point to where you did.
Why?
Pop-cap prevents you from capitalizing on a temporary power burst from low value density units. Since the only reason you're building low value density units is the temporary burst of power in exchange for long-term upkeep losses there's no upside to building low value density units. All you get is the downside of higher relative upkeep.
Without pop-cap a player heavily invested into mid-game units would have about 10 minutes to win the game before upkeep burns out their economy. With pop-cap there's like a 2 minute window to capitalize on before you can't build anymore units and have to begin actively sacrificing low density units.