Yes, but also, most MPs do understand how the system works and will follows its conventions.
A lot of people seem to think that all the MPs who wanted a vote on this were intending to try and block Brexit. But most are not. Even if they personally disagree with the idea, they understand that the people have spoken and they will vote to give effect to Britain leaving the European Union.
But the principle of Parliamentary sovereignty is literally at the core of the British constitution - and so insisting on the right to have a debate and a vote in Parliament is also an important part of ensuring the United Kingdom functions the way it is constitutionally supposed to.
Part of the reason why membership of the EU is a problem is because it undermines Parliamentary sovereignty and the British constitution. Insisting that leaving is done in a way that puts those principles back at the forefront is something I would do if I was a British MP. I’d regard it as the only truly patriotic course.
Parliament must have a vote. But it must vote for Brexit. Those two things are both important if Britain is to be the nation it is supposed to be under its own constitution by its own conventions, evolved over a thousand years.
in hindsight parliament should have voted on the boundaries it could have accepted
Membership in the EU is antithetical to that.