Sure. For instance, if you have equipment failure that means you'll miss a ship date where you've promised to a pay a penalty if you're late, or if it means you'll be unable to fulfill a contract.
Weird things happen. I once had my office flood and was unable to use it until they cleaned it up. I had to take out a loan in order to quickly obtain a temporary work area. Critical equipment can break, critical people can get ill or quit, requiring you to hire a temp to get through a crunch, and so forth. These are rare sorts of events, but they happen. When they do, if you don't have the money in the bank to cover it (and you should never use the money intended for rent, taxes, or payroll to cover these things), a loan can be the best option.
I left out a monetary policy that I think is critical for me, so let me take the opportunity to add it now: avoid fixed recurring expenses as much as possible. This includes buying things on time, or periodic subscription/service fees, etc. It's really, really easy for this sort of thing to get out of control, particularly by stacking up a large number of small monthly expenses.
The main problem with fixed recurring expenses is that they reduce a startup's main advantage of flexibility. If your monthly expenses are low, you are able to be pickier about what business deals you take, or you can afford to cut a problematic customer or supplier loose, and so forth. The better a business can weather lean times, the stronger that business is.
