Let's say the government proposes this and this vote is carried out. Then a majority of MPs are getting something they don't want (otherwise that outcome could be passed as a normal vote by simple majority). In particular, the government may get an outcome it doesn't want, the majority of parliament doesn't want but would have to carry it out (well, that would be part of the earlier proposition of this system, otherwise the vote would be meaningless). This isn't ideal.
Aside from that, those options aren't a one-time thing. These actions have consequences and once you choose an option, you have to follow through:
For example, if you accept the current deal, many laws will have to
be passed (which requires a majority, again).
If they decide to keep on negotiating the impasse isn't broken, they
will just have one more option if a new deal is negotiated, but
there may be no majority for that one either.
Leaving without a deal is like opening Pandora's box, it's not
something that solves all existing problems, instead many more
choices (e.g. what will be the policy on allowing EU citizens coming
to the UK? How are goods coming in checked?) will have to be made
and that requires a majority in parliament to do so.
A second referendum also doesn't help if there is no majority in
favour of it. In the proposed plurality vote, do MPs commit to
respecting the outcome? Even if that means disrespecting the current
referendum outcome? If the outcome is to leave without a deal, what
instructions does that give the parliament / government with regards
to the previous point?
All in all, it's not that easy. And if MPs do decide they want to work together to get a certain outcome, they can just do that. They wouldn't need the plurality vote. For example, the leaders over the parties could meet, decide an outcome, whip their MPs and don't care about a few people not voting with their decision. Obviously, the problem is that the parties aren't willing to compromise in such a controlled setting, they're not going to allow a vote (for which they don't really know the outcome) and then magically decide to respect that.