They caught on, but with more appropriate stainless alloys. Columbus has XCr, Reynolds has 931. Either can be brazed, or silver soldered into lugs, or TIG welded. Cinelli does mass production of the bike you're describing, minus the lugs.

304 can't be optimized to a point it'll compete with the vast range of other stainless steels that already exist. Something else will always be more corrosion resistant, or stronger, or tougher. 304 exists on price. It's quick, common, and cheap. This process makes 304 expensive, uncommon, and slower to produce. The proven concept is what's carrying value here.