How to force quit on Mac? And the most important what is the reason to force quite Mac application? It may happen that some Mac applications crash from time to time, although the rest of the programs and the system itself work as if nothing had happened. A worse scenario than unexpectedly crashing applications is only those apps that stop responding to external stimuli in the face of a desperate user, but continue to function, consuming resources and clogging up RAM with digital garbage. The only way out here is to resort to Mac force quit option.