No. In this day and age we shouldn't be asked this question. They can do beautiful 3D worlds with rich content. They just don't want to. The time/resources excuse is just bull, the programmers do the programming, the artists do the models and the writers do the story, there is plenty of time to be excellent in all departments with the same budget, if you hire the best people and if you know how to reach your goals.
I agree with you for the most part, artists don't program and programmers don't art. But pulling resources from one aspect can certainly improve content in ways of story.
Graphic/sound/whatever artists make art, they don't program they don't script they don't QA.
Writers write stories and quest lines but must also work closely with Content Developers when it comes to technical feasibility, unless they'll write a grand epic that cannot be implemented with the time and resources available to the content developers. These resources include sounds, music, voice, props, 3d models, textures, etc. Content devs are often given a quest to implement and they'll have to make it happen with those things I mentioned without any additional requests for resources and sometimes they'll just have to negotiate a story change.
If less time and resources were spent on making the game such an artistic masterpiece, stories and quests could more frequently be written and implemented without compromises due to lack of those artistic resources. If theres no voice to implement then the conversations and story twists/turns/variations could be increased dramatically. Just like in oblivion you couldn't write a dragon into the storyline cause they didn't have dragons implemented. Etc etc.
I would still vote no, I wouldn't want a 2d isometric skyrim.