I wonder if that's where voters' expectations have now lost touch with the reality of the Labour party;
Voters are used to a lifetime of two party politics and want both the two main parties to provide the option of a realistic government that can win an election by evolving with the times, listening and responding to the majority of voters' beliefs and needs. And there's a lot of tribal history and expectation of what and whom Labour used to stand for and represent.
However the Labour party seem intent now on being a party dedicated to that very specific argument and point of view, with their interest on furthering this rather than engaging with voters and the country, and being an option for a realistic government. Which is fine, but it comes with accepting this won't appeal to many voters who don't share those very specific views and interests, and that Labour isn't likely to win an election. And it leaves voters in limbo with no meaningful opposition.
The time is very ripe for a new centre left party that has its feet on the ground.