The purpose of the ‘Backstop’ was to prevent a hard border between Northern Ireland and the Republic of Ireland. That was the purpose of the negotiations with the EU that Theresa May’s government set up. A ‘No Deal Brexit’ will basically guarantee that a hard border is set up.
The quickest way to guarantee a hard border in Ireland will be through a ‘No Deal Brexit’
The most surefire way to get a hard border between the Republic of Ireland and Northern Ireland will be through a no deal Brexit. If the Backstop is the only method available of preventing this situation then arguments against the backstop will be counterproductive and a no deal Brexit exit will in fact be a betrayal of the Irish leading to a hard border between the 2 parts of Ireland.