I still don't know why the fridge thing riles up so many people. Yeah, it was a ridiculously elaborate setup for what was ultimately a very minor gag (we're talking 'coat hanger gag from "Lost Srk"' minor' ), but come on. Is it really worth dwelling on THAT much? ... or why the presence of aliens (a recurring theme in the '50s) were so bothersome but 'God' coming down and smiting a small band of Nazis - not because they were Nazis, mind you, but because they opened the Ark of the Covenant - and then sucking them up into the sky wasn't. ??? But, no, there's no defending the Tarzan thing. :P
I'm just glad we're definitely getting a fifth movie, if only because the number 4 lacks the finality of 3 or 5. :-X
Actually, the nuking the fridge was a leftover idea from the very first Back to the Future movie. Before using the whole clock tower being struck by lightning plan, the original idea was for Marty and Doc Brown to sneak into a nuclear power plant and cause an explosion to cause enough energy to send Marty back to his time line, while he was inside a lead lined fridge attached to the DeLorean. Obviously they didn't go with that because of how ridiculous it sounded, but for some reason, Lucas thought it should be used 20+ years later. Come on, just reading that description sounds far-fetched, why would it be a good idea? Yes, Indiana Jones is a series that includes voodoo, the Holy Grail, and melting Nazis, but getting knocking several miles away while inside a fridge and coming out perfectly unharmed ... there's only so far you can suspend your disbelief. And, there was no magic involved to hide behind. It's up there with "jumping the shark".
As for the Ark, they foreshadowed in the very description of what the Ark was and how it was going to unleash power that would destroy the unworthy upon being opened, so yeah, it would be a huge letdown if that didn't happen. The story was leading up to a supernatural climax, so yeah, it's going to end with a supernatural climax. And the aliens, yeah, I know it's a trope of the '50s, but again, we're talking about a series that was deeply included by magic and fantasy. It's as big a cop out as the magical aspect of The Force in Star Wars turned out to be bacteria in your blood. Oh ... wait. ..