The Shuttle was never designed to support Lunar missions so that's a red herring.
It was designed to recover satellites and bring them back to Earth safely as part of its military mission. Nothing Space X is offering has such a capability.
The contention was that it was the most capable spacecraft ever flown, without qualification and no reference to LEO, so I think pointing out that it's domain of operations was actually very limited is reasonable.
The shuttle was very well deigned for what it was intended to do, that's quite right, it's just a shame it was never used to perform one of it's primary tasks. However it also doomed the manned US space programme to operate exclusively in LEO for the vehicle's lifetime.
It was designed to recover satellites and bring them back to Earth safely as part of its military mission. Nothing Space X is offering has such a capability.
Different vehicles for different roles.