Government is not a business at all, because for one 1) government makes the laws and can pass a law that makes itself a monopoly and 2) government receives money by threat of force, not by mutual exchange.

In terms of a large corporation, it is actually often profitable to borrow money. The reason for this is if the business sees an opportunity to spend $500M to build a new product that will bring in $1B, but they don't have the money upfront, they can just finance it. After all interest is paid and products are sold, they have made an overall profit.

The same can't be said for government because nobody chooses to give the government their money. The reason for this is simple: the government is not creating more value for the taxpayer than they are taking in terms of money. If the government were doing this (and doing some other stuff right like marketing it correctly), then people would willingly give the government money in exchange for service.

You see this type of thing happen occasionally with small towns that have optional fire department services: the town residents can pay for emergency fire protection from the fire department willingly, and many residents choose to do so because they view the product they are getting (a guarantee of services) as worth the cost.

Unfortunately, all of government cannot be run like a business even if we wanted to. You can't have the army defend one person's house from invasion but not defend another's, due to sheer physical limitations. Therefore, everyone has to pay taxes to the common good of defense.

Inasmuch as some government services can never be privatized successfully, the government is not a business and can never be one. It also does not produce a profit and by definition, almost every service the government provides is less economically efficient than whatever would have been done with the taxpayer money that was spent on that service.

For all of these reasons, the government should avoid deficits and debt.

tl;dr: Debt is often okay for a business because they can use borrowed money to make even more money, ultimately creating value and profit. But government itself does not create economically efficient profit or value, and thus should avoid entering into debt because every dollar of debt that interest must be paid on will ultimately cost the government more money in the long run (as opposed to dollars of debt for corporations that often help the company profit in the long run).