[theoh]

You're taking that line out of context and rephrasing it.

"That said, the overall trend is hard to miss: Luxury isn’t connoted with fussy extras; no-nonsense boldness is the rule. “Spartan solutions have been rampant in all areas of design,” Gardner says."

In other words, the current trend is to use no-nonsense boldness to connote luxury. It is explicitly described as a trend. Fashions change, and the article doesn't deny that or claim to explain why. It might have something to do with increasing typographical literacy among the public, or with the popularity of authentic, no-frills, "vintage industrial" design.