Do countries have to run on deficits? What is their possible economic future? Do countries have to run on deficits? Is their future to behave and act like big companies that produce goods and services?
One of the main reasons for the general tendency to run deficits is political economy. Governments are elected for a limited period and try to stay in power by benefiting their electorate. An alternative explanation is that high debts reduce the scope for the subsequent government. So there are good reasons to impose some restrictions to the deficit into the constitution.

I find the comparison to big companies misplaced. Governments fulfil different purposes than companies. Many of their 'products' are public goods (public infrastructure, education, defense, social security) which cannot be provided by private actors due to external effects. A strictly profit-oriented view of public services therefore falls short of what governments are supposed to do (which does not say there is probably lots scope for efficency-enhancing in most administrations). As a sidenote, running huge deficits is not uncommon to big companies, especially in digital services. As long as creditors are convinced these debts will be paid, companies can be run on losses for quite a while.