Stainless would have been great living in Hawaii... the CES pipes rusted pretty much instantly, but, so did everything, including stainless bolts.
Considering how much work goes into properly welding stainless I do understand why Carpenter pipes aren’t welded, it would add significantly to the cost to find a welder to properly do the job.
Paul’s probably spot on regarding expected use. Track vs Street a track based design may well last a lifetime of track use, and be ruined very quickly on the street.