I think JM can be decent. Maybe better than decent at some point. But right now, he's underperforming in pass protection, and I'm sorry, but that's a problem --- at least for right now. An underperforming LC, causes all kinds of problems with your offense, not the least of which is the anxiousness it creates in a young, developing QB.
And that's where we're at. I trust that Philbin & co made the right decision with Wrong, in fact I supported it then and I support it now, but if we're going to be honest, then we have to take into account that Philbin & co were actively and overtly searching for a LC in the off season, and that indicates that while they're hopeful that JM will develop into the LC they think he can be, (I said it then and I say it now) ... they're not convinced.
Throw in not having anyone even close to decent behind him, and I don't think it's unreasonable for people to be concerned at this stage. Three or four weeks from now this might not be an issue, but for right now? Yes it is IMHO.