The only reason No Deal is still on the table at all is because it is practically the only way the UK can wrest back some negotiating power against the EU - but No Deal is also something of a misnomer. As alluded to above, No Deal is not a sustainable outcome - something will have to be worked out on a whole raft of issues (and formally agreed at a later date), but the question is not just what, but how...
Thus far, the EU have played hardball over the Irish backstop to the point where none of their proposals are acceptable to the UK - heck, the UK Parliament voted unanimously against the EU's original (and preferred) plan, even to the point of making it against the law for the UK to accept such a situation (the 'NI only' backstop). But, they have also succeeded in backing the UK Government into a corner that they can only get out of by either revoking Article 50 or by rejecting the entire Withdrawal Agreement and opting for 'No Deal'. But, deals will have to be done eventually - but the question is, why would the UK agree to permanently disadvantage itself and commit to a legally binding agreement that means, from the point of ratification, the UK is effectively powerless to negotiate? No Deal would, at the very least, hand back some proper negotiating muscle to the UK and level the playing field in terms of what the EU can demand from us and vice versa.
The EU will take a huge hit from No Deal, but all the more reason for the EU to commit to a more reasonable negotiating stance in the future. The EU will, ironically, get something from it insomuch as they can say 'See, if you want to leave the EU, then you cannot cherry pick - you either take what we offer or you get nothing'... this will appear to be true, but the truth of it will gradually change. The reverse argument is also true - a No Deal Brexit will also make Brexiteers very happy in the short term, but that too will probably not last very long as the UK is free to negotiate all manner of new ties with the EU.
It is important to stress what (I think) I am trying to say here, which is that it is not merely the outcomes that are important, but the mechanism by which these outcomes may (or may not) be delivered - and that is one reason why the EU's implementation of the Article 50 process has not helped, because MPs are (rightly) worried that the process itself leaves the UK vulnerable to having to make massive future concessions in order to secure a handful of 'desired' outcomes that might not even happen at all. Perhaps negotiating a future relationship will be easier outwith the Article 50 process where the EU holds most of the cards - and, ironically, the bitter reality of a de facto (and utterly unnecessary) trade war between the UK and the EU might focus minds on both sides and lead to a more pragmatic approach in future.