I think their point is the budget should be passed seperate from any other laws. You don't say "we'll splurge on this vacation only if we agree to split washing the dishes. It's both or neither."
Why do you imagine that non-budget-related issues must be packaged with the budget into the same bill? Parliament may pass as many bills as it has time to.
So politicians can say "I didn't want to extend the copyright, but the budget needed to pass." Plus, passing more things at once limits the average person's ability to take in what they are doing.
Do you have a child as a tie breaker? Or do you mean more discuss with each other potential purchases rather that literally vote on it, which doesn't work very well with two people.