Well, I think that's completely false to be honest (I mean that 3D adds little, not the part about it being more work). What I however do believe is that it may take a while before filming real life/sets rather than relying in CGI will catch up. Having seen Shrek 3D however, it's clear that 3D adds a lot of filmic effects that are actually meaningful. Both emotional closeness and distance work very well in 3D for instance, this added to the obvious stuff like vertigo working much better in a 3D movie than a 2D movie, or the sense of peering into someone's personal space when you're looking from the outside into Shrek's house, a carriage, etc. Shrek is almost a test-case movie that experiments with all sorts of new ways to use 3D to enhance a scene, and imho it's basically a must see for that reason alone. I think it was in Avatar already, but Shrek also makes great use of looking into reflections and mirrors.
I think the point these film-makers are making is that the cost isn't always worth the benefit, where studios are currently thinking that they have to make or convert anything coming out now into 3D or people just won't go see it. So there's a big conflict of interest. I fully agree that a film-maker does not need to make a 3D movie just for the sake of it. But I'm also fairly convinced that it will become the norm rather than the exception in the future - it just needs to reach the point where the additional effort to do so is minimal.
And of course there will also be a fair number of film-makers who are not ready to make that transition and probably won't ever be. They learnt their trade in 2D, saw everything that ever mattered to them in 2D, and 3D just isn't interesting to them, just like my father wouldn't get a surround system at home, whereas for me stereo is to surround as mono is to stereo for him. I'd rather have a surround system at half the quality of his stereo system, as that still sound way better to me. That's not to say I don't hear how great his speakers are for stereo, but I'm really sensitive to the spatial aspect of sound and the simulation of various acoustic environments adds so much for me.
3D will introduce a similar generational border that some will cross and others won't.
Incidentally, both me and my wife, when we walked out of the cinema and into the beautiful city of Utrecht this weekend, suddenly saw the 3D-ness of the world much, much more strongly and sharply than ever before. It was quite amazing, and no adjustment needed at all. The guys who made Shrek must have done something really, really well in that movie.