That's funny how movie nerds tend to flame down the the Kingdom of the Crystal Skull. I had pretty god fun watching it (again). Okay, it's not perfect, yet no movie is, mostly Indiana Jones installments. Yet it's good old B fun, like the three ones before. Like every Indiana Jones, it's set up in the time of the action, with all the vintage : the bomb, the american vision of the communism, Area 51, aliens, etc. But most of all, and that's what people couldn't accept : aliens and UFOs. Not being christian, I find it as easily admissible than any mystic stuff thrown at us so far. C'mon, the ark ? The graal ? Indu gods ? Aliens ? What's the difference ? That's funny how people tend to accept religion based myths and stories when it's their culture. Look at the Kingdom of the Crystal Skull as entertainment, as it was meant to be. Rela. There's everything here : the action (as "crappy" as always : hanging from something, an horrible death, punches, etc), the thing that can't exist and yet is there (aliens... well, that's as good as any ark), the easter eggs, the punchlines, the old studio touch (even with CGIs), the travel, and the "oh my god what the heck are they doing that's so pulp" feeling.
Now tell me you found rational a christian artifact that throws power beams sparing the ones who close their eyes, the cup who let you live for ever with a whole temple crumbling to oblivion, or the voodoo guy pulling off hearts from people still screaming.
You focus your argumentation too much on the aliens. In my opinion, they are only the tip of the iceberg. The problem of the movie is definitly the script. If Lucas would have done some more writing, the flick wouldn't have been so dull. The purpose of all the action seems just to fill up gaps in the story. So, they get off their jeeps and walk for 10 meters, only to stumble upon some crazy ants which try to eat them alive. What the fuck?
What tliff mentions with the fridge is the scale of the action. They exaggerated it big time. Did they try to top everything ever seen in action history?
Overall: good popcorn cinema, nothing more. I expected too much and was disappointed. Maybe I should watch it again on DVD under the influence of alcohol.