It was clear to all seasoned EU-watchers from the morning of 24 June 2018 on that the most likely course of events would be a second referendum aka People's Vote, at which we simply give in and vote to Remain.
With previous unfavourable referendum results, "they" tweaked the terms of the deal to make it a bit more favourable and re-ran the referendum, that's always worked so far. They've modified this plan, which is - and always was, once "they" had dusted themselves down and got over the shock - to agree a Brexit deal that is so shit and so unfavourable that is won't get through Parliament (too many fundamentalist Remainer MPs and too many fundamentalist Leaver MPs).
Hey presto, another referendum is called to 'break the log jam' and a few percent of moderate Leave voters vote Remain next time round, job done, trebles all round!
Doing something sensible like adding "rejoin EFTA" to the referendum options and allowing ranked voting is not on the cards, because "rejoin EFTA" would almost certainly win by default - for a few people (including me) it would be the first choice, for most Leavers and Remainers it would be the second choice - which is not a favourable outcome from the EU's point of view.
So if you are an MP with a conscience, or a voter in the next referendum, you only have one logical course of action - that is to vote in favour of Theresa May's Brexit agreement, however deliberately shit and unfavourable. The alternative would illustrate once and for all that the EU will always get its own way and get away with anything, which is not a good outcome.