briefly, I will respectfully disagree. The Queen, like all the other DGs has her ups and downs. she's not flashy, she doesent do a ton of damage to DGs, and honestly she lacks on a few of her skills (Uproot IMO). That said, her shield rocks, at lvl 4-5 and her creep killing power spikes to devastating potential. I have found at least 1 enjoyable and tide turning build with her, but you have to be happy playing almost dedicated support. alone she is vulnerable. With a killer i.e. oak or UB (or any good DG killing build) she can be insane. if played smartly she is almost unkillable (emphasis on ALMOST) and can prevent a LOT of deaths on her team, as well as let her allies push that much harder.
Well when you look at it that way... yeah. That does suck. Explains (in part) why Queen is least played and least successful.
I think a lot of people simply want to be the ones to get the kills, favor, and power rather than support. Doesnt make her less usefull on a team, just less popular to play.