Fixed-term Parliaments Bill

At Second Reading, my noble and learned friend said that the advantage and the public interest in having a fixed-term Parliament was predictability and continuity, as a Government could then complete their programme over a five-year period. I understand that argument. However, what public good is produced when a Government with a wafer-thin majority lose the confidence of the legislature and then artificially try to create a situation in which a new type of Government with new allies might be formed? Why is that in the public interest? Why have these two devices to try to create a new Government in place of the previous one? I do not see the public interest in completing five years with two different Governments.