However, let's take it on its merits. The distinction it makes between architectural competence (what it calls 'goodness') and style is correct and important. But I don't think it successfully makes the argument that it is easier to be competent using old styles. See McMansions for an example of how a vernacular can be twisted into bricks and mortar (and drywall) horror, and there are plenty more examples of modern interventions ruined by hackneyed attempts at traditionalism. Furthermore, I'd argue that bright architects, most likely to produce competent work, are not going to be drawn to cookie cutter trad style starter homes (for example).
It calls out Brutalism specifically, but that style has been out of fashion since before many of us were born - though remains a favourite bug-bear of the reactionary right.
It rightly notes that architecture is a public art - but given that so few buildings are actually designed by architects (as it also notes), those that are should challenge the public. Not always and everytime, but if art does not challenge us, it ceases to be art and becomes merely decoration of culturally barren lives.
A counter-point to the central thesis - that architecture should be easy: Central Lisbon is a wet dream for this idea, trad everything, and very beautiful too. Yet it feels suffocating and sterile - no room for the future. I'd rather it had gleaming tower blocks, full of hopes and dreams, like downtown SF. Crossing the Bay Bridge in SF you feel a sense of excitement, adventure and potential. Whereas every time I cross the '24th Abril' I get depressed - the most notable feature I can see is the cruise ships parked at the terminal.