It's just one of those things that is hard to accept no matter how many fantastical of things have happened in the past. It just looked utterly silly and not like something at all one could survive. The awning fall and the liferaft fall both were shown to look "kinda" like it could be survivable. Because they didn't show the liferaft landing on the mountain side going Mach-1, tumbling off numerous rocky crags and crashing into things before finally coming to a rest at the bottom of the mountain with Indie looking fine and Willie's hair simply being messed up a little with her screeching about it.
Iron Man gets a similar treatment to the Nuclear Fridge landing, when his prototype suit crash-lands in the desert, after he escapes the cave. I don't believe that he and his cave-mate wired inertial dampeners into the suit. Why does Iron Man get a pass?
I don't think it should. That's definitely a moment that takes me out of the story for a second or two, because it just looks SO unsurvivable. But thankfully it doesn't become a trend (like in Indy 4), and the rest of the movie keeps his abilities to a fairly believable level.