They don't want to balance the budget. They want more money to buy votes with fancy programs to impress our society of spoiled and sheltered little children in adult bodies. The budget will never be balanced until citizens stop sucking their thumbs while crying for mommies or daddies in government to care for and protect them all ways and always.
Because that can be a very bad thing for a country. This is an article about the last time we tried it, in the mid 1980's. http://www.nytimes.com/1987/03/03/opinion/repeal-the-balanced-budget-law.html
It is also no protection from having the government take more money. Romney liked to brag that he balanced Massachusetts budget without raising a single tax, but neglected to point out that he did it by raising fees on hundreds of other government services.
Something that sounds good for a family or a company often just doesn't work when you get to the real world of huge things and huge numbers of people.