I agree with your premise that by 1860 the South was quite prosperous, the Deep South especially, arguably more so per capita than their Northern cousins.
Yes, much is made of the South's alleged backwardness industrially, but that is only when compared to the highly industrialized North.
By global standards the South was more advanced than any but a handful of other regions.
Nevertheless, Senator Wigfall's words are certainly appropriate in describing the South's elite planter class outlook.
They considered cotton & sugar sure ways to wealth, contrasted to industry and shipping as relatively risky.
And Confederate aristocracy came entirely from the planter class, no industrialists need apply.
One result was British traditional aristocrats sympathized with Confederates while industrial middle classes supported the Union.
Fortunately, when the chips were down, so did their elected officials.
As for claims that Federal government didn't support Southern railroads, there is the matter of Secretary of War Jefferson Davis' Gadson Purchase from Mexico for the sole purpose of providing a Southern route for the transcontinental railroad.
At the same time, iirc, Secretary Davis moved to block a Northern route.
Politics as usual...
Interesting.