Very true. A non-profit cannot afford to have a deficit because they are forbidden to accumulate the profits necessary to withstand bad quarters. The "no-profit" requirement also sometimes leads to poor management, if not irresponsible waste. Literally, since there is no profit and no shareholders, nobody is responsible for avoiding waste. This becomes a problem in some large institutions. For example, a very famous Pennsylvania-based charity running an orphanage has repeatedly been accused of wasting donors money because of their non-profit management structure, at a time when there is record poverty in the country.
So finding income sources and assuring the continuity of the institution is not a small matter for a non-profit.