No one had a gun to their head forcing them to be outdoors rather than on sets. If ENT could convey the wonders of space exploration* cost-effectively with sets, why couldn't Stargate do the same?
*Well they didn't actually do this well, but the writing, not the production values, was at fault.
The whole point of Stargate was to explore new planets. The Gates were out in the open for primitive and Goa'uld planets. Now unless the Galaxy started to fill up with advanced aliens they had to do outdoors.
Personally I prefer it that way. Sure the Canadian geography gets boring after a while but it's much better then having a planet represented by indoors while the outdoors is basically just a painting or a model.
Because the writing was so much better. Just goes to show what I keep saying: good writing is the best way to produce a fine show within a budget. I dunno why more shows don't adopt this strategy. Maybe there's a crying shortage of competent writers in Hollywood?
That gets me annoyed too. For to long I have heard people using arguments for a reboot that can simply be solved by having better writing. They make it sound has if canon ruins the chances of good storytelling.
In my mind better writing could solve it. Why specifically have Ferengis or the House of Duras be the bad guys in ENT? No one is forcing the writers to use these guys. They could have just used some random Aliens and a random Klingon House.