A higher role of Parliament is to act in the best interests of the country. That is the purpose of representative democracy, after all. If -- as, by now, should be fairly obvious -- it's seen that a particular policy objective should not be pursued, then it's Parliament's job to say so and to avoid it.
That is where we are with a no deal exit, at least. Every reputable authority on the subject agrees that it would be rotten for the UK, to some extent or another. It is, at the very least, a reckless gamble to ignore that and to press on regardless.
If, in spite of all those warnings, we do leave on March 29th, with No Deal, and no proper plan of where to go afterwards, still -- then I am looking forward far more to being called naive, stupid, and foolishly pessimistic, than to the horrifying possibility of being right.