[kortex]

I think you've nailed the reason they have gravitated towards bolted tube frame design, despite the quite glaring mechanical downsides to that style of assembly. They are driving down the number of custom operations and shrinking the BOM as much as possible. Bolting on more struts is preferable to welding custom angle brackets (which would be more skookum) when that's yet another part you have to jig and fabricate yourself.