If you don't agree with a course of action then by all means do make your point in a constructive way.
But once the decision is made then you cannot shun your responsibility and refuse to implement it. Either "disagree and commit" to the best of you ability or quit.
You can disagree with a course of action and still implement it in a way that won't gut the company. This isn't that. But let's give it six months, assuming they'll make it that far.
If you don't agree with a course of action then by all means do make your point in a constructive way.
But once the decision is made then you cannot shun your responsibility and refuse to implement it. Either "disagree and commit" to the best of you ability or quit.