That's a retarded argument.
It is not that Defensive Technology has lagged behind Weapons Technology, it is that the Aggressor has the advantage in choosing the time and place of engagement. That has nothing to do with technology at all and everything to due with the nature of warfare.
The result is that the defender has to spread their focus thin over wide areas while the attacker gets to focus their attack on the weakest link.
When both sides get to put their best show in the same location, offensive systems and defensive systems have consistently
shown themselves to be roughly equivalent with a very slight
edge to the offensive system due primarily to the cheaper nature of prototyping munitions.
This is, of course, no longer true, given the advent of high-energy lasers, particle cannons (MARAUDER), Railgun CIWS (CCEGL), and super-alloys such as Nanoplate which can according to simulations shrug off even nuclear blasts in armor-grade thicknesses.
Even in WW2, means existed to completely shut down attacks on fleets by aircraft. The 'Great Light Project', just to name one American 'AA' system from 1939
, was the Canal Defense Lights on steroids: giant shipborne focused-searchlights functioning as proto-lasers meant to burn out pilots' eyes. The US Navy balked at the concept in the end and threw it out as inhumane after animal testing proved it to be extremely effective beyond their expectations (they were expecting deterrent, not lethality).
But this isn't the right thread for this.