Like kids in a sweet shop

In a system of direct democracy, would the majority want everything, like kids in a sweet shop, spending every penny... and more?

It must be the role of the government to manage the budget, which puts them in the difficult position of saying "No!"

This paints a picture of voters with the maturity of children. I believe that this is far from the case. The typical adult often makes complex personal financial decisions and can easily understand that governments have finite resources and that wants are virtually infinite and must be prioritised.

That's not to say that the government (and opposition) shouldn't be offering leadership, explaining the limits of what can be afforded, the consequences of decisions and the rational for their own preferences.