Well.. I can see why saddlesores needed to take a break from banging his head against the wall.
Part of the reason you may think people hold such polarized positions is that engaging in theoretical online debates doesn't often reflect what happens in the world. Most bike tourers I know haven't heard of Bike Forums. Online, people tend to amplify minor differences into major objections or necessary determinant factors. In the real world people tend to get by through adopting more middle ground ideology.
You also assume some untrue givens to buttress your positioning. Most people don't think just any welder can weld a bicycle frame in the same way that they don't think any old backyard mechanic can rebuild a transmission. I actually own a welder but don't think I could weld a frame. That's a false premise. Without it, looking at welding bike frames becomes more realistic.
When we look at the particular circumstance where welding in the field may be a necessary requirement, it is probably in a remote or developing region where access to timely shipping and replacement is otherwise problematic. You can't get by without making a repair. In those circumstances, local tradesmen are probably well versed in repairing things like bicycle frames. As with the Pakistan Truck video series linked above, they usually have a well established set of skills based around the need to repair rather than replace. I would probably trust them far more than a welder in the developed world who rarely finds the need to repair a bike frame. In the developed world or close to civilization I could probably also find an alternative solution to the problem.
So you then argue.. They may be able to weld - but not thin steel tubing! Again a faulty premise. On the one hand you argue people will not choose an aluminum touring frame because it is too fragile and difficult to repair but then try to assume they will alternatively choose a fragile and difficult to repair steel frame. Why? Anyone who is looking
specifically at frame material for strength and repair ability will probably also consider build quality and select for robustness within the material subset.
Will you next argue that such frames don't exist in the same way you argued aluminum touring frames don't? Surly you don't think that. btw, here is an answer to that earlier statement:
https://www.koga.com/en/bikes/trekki...veller?frame=H
The whole argument about group sets and tiers is just too much of a rabbit hole to pursue deeper. Most people understand that lower tier components can be strong and affordable but are somewhat clunky (less precise) because they are less refined. As you ascend the tiers you get strength and lighter weight (which also creates precision through refinement) but at a higher cost. They also understand that for racing one might require such precision but for touring that is not a driving factor to the same degree.
Everybody also knows race bikes can last more than one race (but don't feel the need to state such an obvious thing). Yet they also get that race bikes don't "need" to survive more than one race, in the same way that a expedition touring bike needs to survive an entire tour in a remote region. When we watch racing we will occasionally see a person who is eliminated due to some failure pick up the whole bike and smash it on the ground, destroying it. The need for that bike is finished. On a remote tour people don't pick up the bike and smash it on the ground because of some failure. They need the bike to last longer than that moment. The show must go on. The bike must survive longer. Subsequently they prioritize selection for robustness rather than lightweight precision.
Tying this all back to the core discussion: In a remote region where repair becomes a necessity rather than a choice, more people will probably have the skills and tools needed to repair steel over aluminum and to repair either of those over carbon fiber. The degree where this transcends the theoretical in an online discussion depends upon the degree to which that access will be required, and how necessary that access is to the survival of the tour (and I suppose how necessary survival of the tour is to survival of the person). It's a sliding scale of anticipated need, and the people at the far end of the spectrum will probably put a lot of thought into it and not assume such things like: "everybody can weld it" or "because it's steel choose thin walled tubing".