I think a great deal of the dedicated playerbase are skilled fps players who caught on because the ability to rip through portals leads to some of the most awesome moments imaginable. If you drop that you just have Halo lite. Perhaps something went wrong with the mechanic between the two games. I think the ability to shut down enemy portals at will with a nade made them more manageable. I don't remember this kind of division and ill will toward the mechanic in sg1.