When you're a kid, you don't always evaluate things the same as you do later in life. I watched the original 1973 film last night and was struck by the cheesiness of some of it, the poor dialog, plot holes and bad explanations for various elements of the story.
What really hit me as I was watching though was that James Cameron must have drawn considerable inspiration for his original Terminator film from the gunfighter character played by Yul Brynner.
What the HBO team has done is taken the seed of a brilliant concept and updated it in ways that not only make it more plausible, but make you think much more deeply about the directions that soft robotics and AI could go and the possible ways in which that technology could get away from us.