7 Things about Terminator

1. Mortality

One of the themes that made the first two Terminator films stand out: the mortality of their cast. This is best represented by the fact that Sarah Connor was the only survivor of the first film, and in the second Sarah and John survived, but almost everyone else ended up toast or slag. The second slightly more subtle nod to mortality is the fact that Terminators are metal skeletons. 

2. Family

The first two films, the only two worth discussing in a positive light, have family as a theme, and they create a stable closed story loop, Reese traveling back in time to become the father of the resistance leader he serves in the bleak future, and John surviving and finding a father figure in the T-800 sent to protect him. As much as this theme is bludgeoned where it's appeared in the Fast and Furious franchise, those movies have a huge following and made literal mountains of money. The later abominations in the franchise completely screw the pooch on this theme.

3. The Singularity

A common fixed point in the franchise is that some variation of Artificial Intelligence goes rampant/out of control and decides to destroy humanity, usually after granting itself major decision making powers. This is a pretty basic representation of the technological singularity, as this AI/Skynet makes its own decisions, actions, and rewrites itself, evolving and growing under its own direction, and not that of humanity.

4. The Inevitability of Self-Destruction

Judgement Day is a condemnation of the violent and warlike nature of mankind, and how we will eventually wipe the species out in a thermonuclear conflagration. Ultimately, the singularity and Judgement Day are products of military research and development, looking for a better and more efficient means of waging war, and succeeding wildly.

5. Time Travel Bullshit

Jesus, trying to keep up with multiple timelines is more of a task than even the films can keep up with. The first film attempts to remove the mother of the Resistance leader before he is born, the second attempts to kill the Resistance leader as a troubled teen. Then, I'm not sure, I think we need Dr Who to unravel the mess we have now. 

6. Fear of Technology

The fear of technology is not new, and the first two films create time traveling robot skeletons that hunt us down and kill us before we're born. That is pretty damn terrifying, and in no way user friendly or convenient. In many ways it is almost an inversion of the John Henry allegory, where the man defeats the machine. The Terminators cannot be stopped, cannot be reasoned with. Can't feel pain or fear. They can kill hundreds without taking serious damage, and actually stopping basic series Terminators takes heavy industrial machinery or heavy military hardware, stuff most people don't have. This means that even well armed people are not capable of defeating the robo-skeletons. 

7. Practical Effects

I need your clothes, your boots, and your motorcycle.

The first few movies had limited digital special effects, by modern standards. The stuff looked real, it acted real, and the liquid T-1000 worked so well because of all the associations with mercury, mirrors, and such. The later mimetic and nano-whatever Terminators are CGI disasters, and they do not evoke fear or a visceral reaction.