Masao (and others) took the idea presented in "Balance Of Terror" to heart and their designs play on the idea of a 22nd century being decidedly less advanced than TOS. When it came to ENT they just wanted to continue doing contemporary Trek a la TNG-VOY and mildly redressed it.
I never cared for how ENT told its stories and I cared even less for how they depicted the 22nd century setting. But then I couldn't stand how they treated Zefram Cochrane and the 21st century either. It was straight-up revisionism and not giving a shit about what TOS established or the idea s they were trying to put across.
I've told him this for years, and I love Masao's eye for detail and imagination. SOME of his vessels look amazing.
But, taken as a whole, his designs look a little too Micro-Machine to me.