I think it's impossibly difficult to argue that wasting time playing WoW is fundamentally worse than, say, watching football.

If someone watches football as obsessively as folks play WoW then I'd agree. But if your child falls over and needs attention you can get up and deal with it without "letting down your group/team/guild". I know of multiple cases of child neglect by players... indeed, my wife and I gave up WoW cold turkey when we realized one of our twins had a fever and we hadn't noticed for several hours because we were so engrossed in the game. Haven't played seriously since.

That is true of most team based activities. I think the difference with online games is kind of like working from home. Other people living with you may expect you to be present whereas really what you are doing is similar to being on a sports team. No one expects you to be present to do other things while out on the sporting field in the middle of a match.

Granted the time invested is likely a little different.

Or to flip it around, playing WoW during babysitting is like running out to go play a match on the field.

Holy cow, where were the kids? Were they crying during sleep time or something?

/posting from my kid's room while she falls asleep.

They were in the room with us in a playpen.

I challenge you to find ten.