Even if this was to happen, I wouldn't be excited. The original movie was pretty weak (although it was still better than Stargate Universe, which was barely a Stargate series) and SG-1 was what made the series as famous as it is, so I don't see how ignoring that would make for a good movie. Besides, after star trek, when I hear that a franchise I like is getting rebooted, I just can't think of it being any good. It could be done, but honestly I'd rather them just let the franchise stay dead.
First off, I don't think the Stargate movie was better than SGU but that's because I think SGU was the best of the entire franchise. Second, your position that you would rather see a franchise die to cling to your aging memories of them rather than see them continue in a rebooted mode just makes you nostalgic fanboy rather than someone who really has the best interest of a franchise at heart. Stargate is fast fading from public memory and Star Trek was also gradually slipping from public consciousness before the reboot sparked renewed interest.
I'd rather a franchise survive and grow than die because I may feel some angst about all my "accepted fantasy related" beliefs might be threatened or re-imagined. In fact, I find it odd that so many aging fans probably share such a childish reaction. But that's just me.
Well, comparing it to Star Trek, I despise the star trek reboot. I also consider the reboot's existence more harmful to the franchise than if the franchise had just stayed dead, because now we'll almost certainly not get a real movie/series and instead get just this watered down action junk with the ST name for the forseeable future. Staying dead is a better alternative than a bunch of junk being released under a franchise's name. Because of that, I definately don't support a Stargate reboot, especially not in movie form and completely unrelated to SG-1. Best case scenario, its an good movie. Worst case, its terrible but sells well (like Transformers and JJTrek) and we get a continuing series of horrible stuff. What would actually happen if it gets made is probably somewhere in the middle of those two scenarios, but after star trek I can't support a reboot of anything, especially not of a sci fi series I really enjoy.