Just to throw in my 2c, I agree with Spoon... the whole thing with different boards and child boards is ease of access... to categorize ideas so that they are easy to navigate. If a board is dead, so what? I mean, unless it is a Mod board, then that's bad for them maybe. But if you had separate (for example) PC Hardware / Software boards in Gen Disc and they were dead cause no one needed support, well then, when someone needs help, then they won't be dead now, will they?
The only potential negative impact I can forsee is if people "surf" the boards, only checking the ones marked as "active"... then I could see a request for help or somesuch getting overlooked. But, IDK about everyone else here, I just use "show unread replies", then "show all unread posts since last visit", check what I find interesting, then "mark all posts as read".
Thoughts?