No, I don't think so. In a Westminster system, the collective responsibility of ministers to cabinet and the consensus decision-making process are absolutely fundamental. One could argue that it's the defining characteristic of a Westminster system. It's what differentiates that system from a republican government in which you have various levels of government that all have power and collide, so as to end up either in deadlock or in some compromise.
The beauty of the cabinet system is that by bringing together a collectivity of ministers from across the country and driving decision-making on a consensus basis, public policy is developed in a way that attempts to meet the expectations of Canadians. Ultimately, of course, it's a matter of political judgment.
I think the notion of individual ministerial responsibility to Parliament for the conduct of his or her department is perfectly compatible with the notion of collective responsibility. The idea behind collective responsibility is that once the government has made a policy decision, all stand behind that decision. If a minister feels he cannot in good conscience stand behind that policy decision, then his option is to resign from cabinet.
To my mind, there's nothing incompatible about, on the one hand, having a government speak with one voice and, on the other hand, having individual ministers responsible for the powers, duties, and functions that they're discharging under their statutory mandates.