It's not Wheeler that's a defensive liability. It's Connor and Laine. Can only expect Wheeler to carry them so much when he literally has to do everything on the ice when playing with these two.
I don't mind this at all. I wish Lowry was healthy though.
Wheeler has caused more than his share of problems defensively on that line. I'm not absolving the kids for their shortcommings but blaming them for the whole line is the easy way out and not indicative of Blake's very poor play in his own end as a C (Not surprising as its not his actual position)