I'd go!

I feel like one of the reasons the general moviegoing experience has failed to expand to include senses other than sight and sound is that the goal of most movies isn't to convince you that you're experiencing something, it's to make you empathize with characters who are experiencing something.

Sight and sound are fantastic senses for triggering empathic mirror neurons and making us think about how someone else feels in the scenario we're seeing and hearing, but other senses like smell, taste, and touch primarily trigger a personal response rather than an empathic response. Those senses are about me, not about other people.

So if I'm watching Die Hard, I absolutely want to be blown away by the visuals and the sounds because that helps me empathize with John McClane as he fights the bad guys. But actually smelling McClane's sweat or tasting the blood in his mouth or feeling the glass in his feet would pull me out of the movie, because suddenly I'm feeling those things as if I'm doing the things John McClane is doing, but the point of the story isn't that I'm doing those things, it's that John McClane is doing those things.

On the other hand, if I were watching Planet Earth or Jiro Dreams of Sushi, it would be amazing to smell the Serengeti or taste the sushi Jiro's making! Those kinds of films would be immeasurably enhanced by engaging my additional senses, because their purpose really is to put me in the moment as if I'm really there.

This is a great explanation. I feel the same reasoning applies to 3D movies, which I try to avoid because for me they add nothing while costing more and giving me a headache.

Regarding your last paragraph, there are indeed situations where engaging other senses makes sense. I remember visiting a museum about the different climatic regions of the world. One of the installations was a dark room with huge video walls showing desert imagery with duduk music playing, while the room was heated to probably >30°C. In combination, this was really intense.

I would visit the "Smeller 2.0" (funny name, by the way), but I agree that it probably wouldn't be too useful as an enhancement of regular cinema.