There will always be payload that pushes the rocket to its limits, make a rocket with larger lift capacity and payloads will increase.
However, they can build that into the cost of the lift. If the rocket isn't recoverable because of what they want to put in it, just charge them for the rocket.
Maybe... Elon is pretty firmly committed to reuse though. SpaceX is occasionally flying expendable now because they have to compete with Ariane and Atlas. Once Falcon Heavy flies, there won't be any such pressure.
However, they can build that into the cost of the lift. If the rocket isn't recoverable because of what they want to put in it, just charge them for the rocket.
Either way it is better than what we have now.