It's really hard to argue nepotism in the case of Shane here. If he was hired at VaTech as head coach, there would obviously be that concern. However we may feel about the hire, he spent a couple decades as an assistant across several programs. I can assure you Kirby and Lincoln didn't hire him because of his last name. So, he's paid his dues in coaching in that respect, particularly starting out as a GA at a school different from the one where he played and where his father coached. I'm sure his last name helped him break into coaching as an assistant, but so what? He started at the bottom.
The most likely explanation is simply that he was a former coach here under our most successful head coach and came highly recommended by former players. It's arguable whether that rationale was sufficient justification for the hire and we'll have a concrete answer in about 4 months or so.
I don't really see the nepotism angle here, though.