If you know more than me, then isn't it incumbent on you to venture an opinion on why we're in the situation of trying to avoid a hard border? If you're asking

If you know more than me, then isn't it incumbent on you to venture an opinion on why we're in the situation of trying to avoid a hard border? If you're asking for my personal, subjective opinion, then I think it's a combination of two factors. Firstly, there are the local issues. Taken in isolation, avoiding changes that would unnecessarily restrict crossings at the NI/Ireland border is obviously a good thing, particularly for the people and businesses near that border. Meanwhile, closing the border has little upside for anyone at this level. That means maintaining the open border is a solid vote-winner, like having more funding for the NHS or more teachers in schools. Any resulting costs will be elsewhere, in this case at a national/international level where potentially the open border could conflict with other possibly desirable outcomes. But of course there are complicated legal issues involved because of the history, and on top of that there is an implied threat of violence that can be invoked. It is very easy to paint a picture where changing the Irish border causes Very Bad Things to happen, and thus not changing the Irish border becomes an attractive proxy for blocking those other outcomes if in your view they are not so desirable but it's harder to make a direct case against them. In short, there are important local considerations, but at national/international level it's also a convenient vessel for blocking other changes that some parties don't want. It's probably a rather cynical point of view, but the proxy debate going on here does remind me of the people in the UK who suddenly became constitutional scholars and fierce advocates of this concept they'd never heard of a week earlier called parliamentary sovereignty, right around the time that a referendum widely advertised as giving the people a final say returned a result they didn't support but it turned out that constitutionally the referendum couldn't be binding after all and the current balance of opinion in Parliament might go the other way. It's a very large scale version of getting bogged down in legal technicalities, unfortunately at the expense of more reasoned debate on the underlying issues of substance.