Finn said:
I thought the motivation was quite obvious - to stop the Reds from claiming whatever it is that waits at the end of the road. Incidentally, you could argue that the very same reason (to stop the MacGuffin from falling to the hands of the bad guys) has been at least one of the motivators to take the quest in the preceding three films as well.
Also, he's obviously in it for personal glory. As a matter of fact, there's a line stating he almost died of typhus while looking for the city last time - so why should he go home now and suffer another failure?
The issue is not that any of these things couldn't be argued. The issue is that the film lumbers into its third act when more dramatic and effective options could have been chosen. It's incredibly inert compared to the high stakes setups for the other films in their respective home stretches. I'm not prepared to defend it as "subtle," either. It's just lazy.
Finn said:
TBH, does he have any higher reasons than self-gratification to go after the MacGuffin in Raiders or ToD either? Not that I recall.
Okay, but we're shifting away from the issue of what's propelling Act III now and talking about Indy's impetus for getting out of dodge early in the movie. The Act III kickstarting moment in Crystal Skull is Indy's "Because it told me to." At the equivalent point in the other movies Indy is far more dramatically invested because Marion is kidnapped (Raiders), Henry Sr. is shot (Last Crusade) and...geeze, where do you even begin with Temple?
It's true, Indy arguably heads to South America in Crystal Skull for similar reasons he starts his journey in Raiders. Here's my problem:
1) In Raiders, Indy's drive in the beginning is singular and well-defined. The weight of the ark is effectively and efficiently established not just in words but because of what the script gives Ford and Elliot to work with performance-wise. No such equivalent in Crystal Skull.
2) Crystal Skull actually proffers a number of potential motives for Indy, but more is not better, at least in the clumsy way the film hands out information. The movie could have clearly portrayed that Indy was heading south to avoid the Feds - but it's not that, because without Mutt intercepting him, Jones was headed for Germany. Is he going down, then, to rescue Oxley, who he apparently knew personally (nevermind our relationship with him)? This isn't clear, either. He isn't doing it to evade the Russians, because he's in fact following them. Maybe he's going to Peru genuinely to help this random kid's mom (the script inanely prevents Marion's identity at this point). Or, as the deleted scene implies, he's headed there to clear his name. There's a bunch of possibilities and none are given any weight or clarity. Yes, I can believe Indy would get on the plane for some or all of the above reasons. But it's
weak and muddled, and completely unnecessarily so, and there's no analog to
that in the preceding movies.
Finn said:
Finally, you could say there are some additional stakes in it as well. They're subtle, but there. Keep in mind that Indy was accused of collaborating with the Soviets after the warehouse scene. Finding the prize and taking it home means clearing his name, while just turning tail and letting Spalko carry on and win would probably spell the opposite. You could say it's a futile exercise because it apparently happens despite him coming home with nothing to show for it. But hey, that's yet another recurring theme when you look at the original trilogy.
The problem is that we don't KNOW it means clearing his name - we can only assume it does because the ending tells us so. There's a reason why the Darabont draft, which treated the innocent-man-on-the-run element with far more attention, saw fit to include the state department character in the jungle adventure. How in the hell does finding a lost city ameliorate the Fed situation? Is there proof that Spalko's team or the city ever existed after the valley gets flooded? Again, I don't interpret this as some audience-respecting, fill-in-the-blanks-yourself approach; it's straight-up poor storytelling. It's the path of least effort.
Finn said:
As final pointer, which is arguably a bit more meta and thus could be considered apologetic, but does there need to be a motivation? Indy is an established character, and obviously a product of an era when men even in real life, like Sir George Mallory, did not go after something for any other reason than it simply being there. As a matter of fact, you could say it drives some men even this day...
Again, this is not about plausibility, this is about providing forward momentum in an action/adventure script when it is makes perfect sense to and would be to the improvement of the experience. Yes, you can absolutely take the auto-pilot approach, as Indy4 did. And I'm absolutely gonna call it the lame missed opportunity it is, even if it "got the job done."