Theory? I've been doing auto body repair for 20 years. I know what I'm talking about.
-S
Consider this. My father's '76 Chevy pickup rusted out to the point of needing major body work in 6 years. That is a fact. The riveted repairs lasted at the very least, 10 years and was still completely solid at that point. So what is wrong with riveting again? Under the same Maine conditions, the riveted repairs lasted longer than the original unrepaired sheet metal. Similar deal with my '83 F100. After 10 years (1993) you could see the ground through the floors on both sides of the cab. The riveted repairs lasted at least 8 years and were still completely solid.
So you have seen examples of riveted repairs that rusted out quickly. So have I. I have seen all manner of repairs that have rusted out quickly, including welded repairs. But, obviously the fundamental problem is not with riveting or welding, in and of itself. Preparation and finishing work is what is important. There is no "rule" or "universal law" that riveted repairs will rust out quickly because of overlapping sheet metal; because if there were, you could only explain my father's truck with magic or voodoo or something. Is 10 years with not a spot of rust not good enough? Will Paige still have his 'Burban in 2016 do you think?
Now, you can explain how to make good welding repairs because you have experience with it. I can't explain how to make good riveted repairs because I have never done it; I only know (for a fact) that it
can be done because I have seen it.