But everyone has been in a situation where they lack a certain critical resource to build a certain critical unit or a certain critical building, and, for whatever reason (logistics or even straight-up roleplaying) they can't get it....
And I think all of that is _good_.
a measured mechanic ... It would require careful planning (to make sure you pop the correct GP for the resource you need), risk (because it might pop a different resource than what you need), and sacrifice (losing the GP to do it).
"A measured mechanic" sounds right. However, I'm dubious about how "careful" the planning would need to be, and how much of a sacrifice a GP would be when balanced against the result. The risk of getting the wrong resource, OTOH, might make the mechanic risky enough.
I think players should be able to play the type of game they want to play.
I agree... with certain important qualifiers. I think what we're discussing is a very basic distinction: Civ4 as "game", and Civ4 as "software toy." There's nothing wrong with either way, but the desired level of challenge vs. freedom is probably very different. With a "game" challenge is generally more important than freedom. With a "toy" that's reversed. I see the Resource system as a fundamental part of what makes Civ4 challenging, a good "game" to which you sometimes must adapt, or lose.
Another way to get resources - if it isn't carefully "measured" - undercuts that system. Great for Civ4 as "toy", not so good for Civ4 as "game.
If the mechanic doesn't tick your tock, don't use it.
I find refraining from using certain tactics, units, etc. very unsatisfying. I'd much rather mod it, remove it, or, sometimes, advocate it not be included at all.
But if a player wants to play a Builder-style game without having to war with their neighbors in order to get the resources they need, they should be able to do that as well.
I think we've got two fundamental points of disagreement. That's the first one: I don't agree any Resources are "needed" to play, or that there "should" be another way to get them. If I'm playing a Builder-style game I either shift "styles", or muddle on without. As an evil civ, as a matter of fact, I relish the excuse to nurse a grudge.
The other point, or maybe it's just an extension of the first, is: I think resources are already too common. Even after moding things a bit I still find myself in the position where I lack a desired Resource less often than I'd like. So, obviously, I'm going to see any mechanic that makes getting Resources easier in a poor light.