With parties you have to take a whole bunch of policies you cannot chop and change and pick the ones you want. You wouldn't go to a shop and let them tell you that you can only buy the red bag or the blue bag and you have to take what is inside. Parties make selection of your true opinions impossible. Do they need to? Do policies have to be connected? There is a strong argument for spending and taxation policies as these have to be connected, but the devil is in the detail.
Parties also make it easier for lobby groups to interfere with government. If we got to pick and choose policies then the lobbyists would have to lobby all of us. They would have to get access to all of us and this is going to be incredibly difficult. It is much easier to lobby a party. So that is another good thing.
But most of all the world or the country run by a politician is a complex thing. So policies have to change. What you wanted to do might no longer be a possibility because things change. You have to be pragmatic and to know when to ditch ideology. The problem is that with parties the ideology trumps the pragmatism and we end up with failed policies and a triumph of ideology over reason and evidence. Rhetoric wins over reason.
So if we want good government we want politicians who are pragmatic, who are no dominated by ideology, who can talk across party lines and we need journalists who appreciate this without looking for splits. So what if Lib-Dems talk to Labour - we should be encouraging cross-party relations, Churchill did.