I think there was definitely a push to sell it to the online players; AFAIK it was supposed to be "as well as" rather than "instead of" people who prefer the single-player do-your-own-thing type of gaming though I can understand why it may not have come across like that given certain other publishers' relentless attempts to drive people into online gaming.
From my perspective I just like messing about with models and textures for the most part so I never really looked into its capabilities and aims beyond that; much the same as when I managed to mod Ego Draconis, "modding" was strictly limited to changing some meshes and stuff. The last time I did anything more ambitious was probably Oblivion or FO3 or something like that.
