There are now a fairly large number of MPs who are no longer aligned to the policies of their party, or who have moved party. An election should shake all of that out.

This, combined with the speaker's constitutional innovations have led to a situation where we have a government which can't govern. Again, an election should sort this (and may allow the removal of an activist speaker as well).

And yes, it will be about voting for a party which matches your preferred strategy. Tory = no deal. Libs = remain. Labour = ??? + radical socialism.