My thoughts are like this:
Movie started everything off with the big menacing and mysterious threat from a hideous and fairly powerful species. Jack in the movie only managed to kill him by default. Not because he was a better soldier. But because he was pushed into a corner and desperate. We are all left to think at the end that the threat has ended with the death of Ra.
Series started off by carrying on where the movie left off, but only now the humans find that the threat has not gone, that there are more of Ra's kind and they aren't a nice bunch of people. I decide to watch it because this is a promising continuation of a fascinating concept.
For some reason, known only to themselves, the production PTB decide that the enemy is to be neutered, but not yet annihilated. Based on what, I cannot fathom, except that there is a rather typically US need to be thought of as an invincible super power, so even in something as small as a TV show, the enemy have to have their claws pulled and their fangs drawn. It is unacceptable for the viewers to be subject to the sight of the might of the US Military being battered into submission by a bunch of aliens. the fact that in reality the Vietcong did exactly that to the US military and they were human themselves is beside the point. The US military have never forgotten their defeat in Vietnam. Even though it was hardly their fault.
At any rate this desire to be seen as 'top dog' no matter what is reflected in many films and tv shows, and it often colours what scripts pass muster and which ones don't. I have even had this discussion with a couple of American movie and tv script writers when I worked for Polygram and they said the same thing.
So the Goa'uld are minimised, and turned into a comedy hall joke. So now we don't really have an effective threat, so the writers come up with lego bugs. They apparently don't think or feel, so it's okay to not worry about killing them.
But you can't bore the folk with lego all the time, so what to do? We develop the SG1 characters, hint at their lives outside the base and their friendships and caring for one another.
But some fans may get fed up with that, so what to do next? You add a little internal intrigue with people like Maybourne, who then, unfortunately, turned into a somewhat 'romantic' sort of figure, a character who did a Hannibal the cannibal and went to a tropical island instead of back to a jail cell. Now they're left with a gap, so they fill it with an even more sinister character called Colonel Simmons who can apparently summon the might of the sneak beaky Pentagon department at the flick of a finger. And he has the nerve to interrogate SG1.... gasp!!
If you add to all of this, the apparently easy peasy lemon squeezy killing of a slack handful of the now neutered System Lords - who have had their teeth and claws pulled, so they can't bite the other puppies any more - a smidgeon of Action Daniel, stoic Teal'c, defiant Sam and heroic Jack, some incompetent Jaffa and a few bits of angst with an alien, you have a recipe for a satisfactorily dampened down, but still entertaining show that the poor little viewers can watch without their consciences being pricked by such nasty things like threats from other species or even whether there was some other powerful species on earth before the Americans.
Sorry, but this is how it has developed in my view. And everyone just buys into it. Not that they are necessarily wrong. It's their choice. I would just like to see one American tv show or movie that didn't insult my intelligence or stretch my credibility level. I would love to see one that made me sit up and think.
Stargate the movie, and the first showings of Stargate did that for me. But don't do it for me any longer. Yet I still watch in the hopes that they will prove me wrong. I could be a lot more comprehensive in these declarations but I don't want to take up the whole forum!
PHEW!!!! That certainly stretched my brain at 1am!!!