&gt; because why would MPs accomplish anything in the next 3 months when they've accomplished nothing for the last 3 months?

Plenty of things could happen in the next 3 months - TIG could swell in size, a general election could happen, a new Tory leader/PM could be elected, ERG could break away, Corbyn could resign, parliament could officially rule out no deal, polling could swing further towards Remain. 

Yes, it's likely that nothing will change, but frankly the main issue is that people still believe there is a good version of Brexit out there somewhere. Eventually they'll realise that there isn't.