He's most likely responding to the fact that the future changed several times since the first time a Terminator Attacked. Each subsequent alteration of the future has pushed judgement day back, but not stopped it.
From Wiki on the first movie's premise:
Skynet is positioned in the first film as a US defense computer system by Cyberdyne Systems which becomes self-aware and, on perceiving all humans as a threat, seeks to wipe out humanity itself. It initiates a nuclear first strike against Russia, ensuring a devastating counter strike and a nuclear holocaust, wiping out much of humanity instantly. In the post-apocalyptic aftermath, Skynet builds up its own autonomous machine-based military capability, which includes the Terminators used against individual human targets, and proceeds to fight a war against the surviving elements of humanity, some of whom have organized militarily into the Resistance.
And the second:
Sarah learns that the man most directly responsible for Skynet's creation is Miles Dyson (Joe Morton), a Cyberdyne Systems engineer working on a revolutionary new microprocessor that will form the basis for Skynet.
They learn that much of his research has been reverse engineered from the CPU and arm of the previous Terminator sent after Sarah. Convincing him that these items and his designs must be destroyed, they break into the Cyberdyne building and retrieve the CPU and arm
So they push back judgement day, but they leave behind the first terminator that then lays the way for Skynet's development.
And in the third:
After the destruction of Cyberdyne Systems in Terminator 2: Judgment Day, the United States Air Force took over the Skynet project and it is being headed by Kate's father, Lieutenant General Robert Brewster (David Andrews). However, the trio arrive too late to stop him from activating Skynet in an attempt to stop the spread of a massive computer virus.
So now, Skynet has instant access to the Military computers and other resources, and also more modern materials, judgement day having been pushed back to 2004.
Due to the element of time travel and the consequent ability to change the future, several dates are given for Judgment Day during the franchise. In Terminator 2: Judgment Day, Sarah states that Judgment Day will occur on August 29, 1997. However, Terminator 3: Rise of the Machines shows that the Judgment Day holocaust has been postponed to July 25, 2004.
So with skynet able to use not only the more advanced but also military technology (seen in T3) it no longer has to develop the Terminators and that technology itself. This is what makes the new and improved judgement day that much worse.