Mega-church, Mega-architecture?

I've returned several times to this slideshow from Slate magazine, of megachurch architecture. By the eminent Wytold Rybczynski (highly recommend any of his books, BTW).

He rightly points out their main architectural flaw-- sheer size makes most of them awkward and badly scaled--and touches nonjudgmentally on a more significant design issue, that they are 'relentlessly secular', pointedly lacking in any ecclesiastical symbolism or traditional religious imagery and easily mistaken for a performing arts center or corporate headquarters. Which perhaps they are.