I completely agree. I don't think the "WMTV" brand is strong enough to stand on its own (I'm not even sure that a majority of Madison TV viewers are aware that channel 15 is WMTV, much less call them by that). It's a very different situation than WKOW, for instance, which has used their call letters in their branding for as long as I can remember and has a lot of built-in equity in their local brand.
Gray's decision to drop network branding unilaterally, regardless of market conditions, has left me scratching my head. Not to discredit the hard-working staff at WMTV, but I just don't think that their brand can hold its own against NBC in the Madison market.