Decisions also need to be implemented in a way that is both achievable but also beneficial to the country. As someone who disagrees that Brexit can be either, I naturally have a great deal of sympathy for the MPs who are arguing this. But even setting that aside, there are still politicians across the House representing a great many views. There are passionate Brexit-supporting MPs who argue for "No Deal" Brexit*, such as Mark Bridgen, Sir Bill Cash, Mark Francois, Sir John Redwood, Jacob Rees-Mogg et al. Whether they are the most honest MPs in the House or not is a matter to debate, but the point is that no matter the side you are on, there are politicians representing you. Never voting again can only serve to increase the chances that their voice in Parliament is lost.
*They tend to give it different names, but it's the Brexit you're wanting all the same.