Why would your customers want you to stop maintaining the software they use and have already paid for?

In that line of logic your competition has a new incentive for you to NOT go bankrupt (perhaps buy your company before that happens?)

If you're of sufficient size that you are a risk to a company's bottom line, I've got news for you: they probably already have a stake in you going bankrupt. Companies buy insurance against their business partners going bankrupt all the time. One such means is called a credit default swap (CDS).

...if your customers believe that maintaining your code can be done more cost-effectively than the rates you're currently charging them.

(and note that cost-effectiveness != cost -- they're correlated, but not the same)