This is a post on the terminatorfiles.net forum that I have copied and pasted. I think what this person is saying is all very true and really highlights some of the problems with the later Terminator films.
"Am I like the only one to feel that? Am I becoming an old ****? I feel like, all Terminator movies except of 1 and 2 lack some kind of epic drama, human feelings, I dont know how to explain it, a soul.
In the T1 the drama element was about Humans fighting and ready to do whatever it takes, sacrifice their lives for the future of Mankind. You see movie full of emotions, check these scenes from future, where you see men chasing and eating rats, women crying, but still these tough spirited soldiers who dont flinch facing merciless and soulless robotic assassins.
In the T2 you see a cyborg, basically a living computer to which a Human program had been uploaded. And more it lives with humans, more it learns of Human ethics, and applies it with robotic unstoppableness. You actually see human ethics work through the Machine. T2 is full of really powerful emotional scenes: scene where John wants to free his mother from Pescadero Clinic, where he cries in the car, because Sarah is surprisingly cold to him, extremely emotional and serious scene in Miles Dysons house, where Sarah, knowing that she must kill the creator of Skynet, knowing the future still is not able to kill an innocent human being, scene with John and Sarah which follows right after, where Sarah feels divided, and regrets her weakness, and where John says how much he loves his mother exactly for her humanity and mercifulness. By the way very powerful character of Miles Dyson, who had consecrated all his life to develop Skynet, and who is ready to sacrifice his own life to destroy it only several hours after having learned what it will do with Mankind, and the death of Dyson is very dramatic. Than take Terminators final fight in this factory. Its very epic and dramatic, with excellent music, you feel like seeing fight of Titans from Greek tragedy, one is fighting to save Humanity and another to destroy it. T-800 revival scene is epic!
And after having watched every single Terminator movie right after it was produced, I have found that all of them had lost this drama, this seriousness, this deep meaning. They all become some kind of soulless, special effect, money machine blockbusters."