It's worse, because there are languages that encode interruption into the error handling functionality, so it's common that people mismanage their errors and programs require several Ctrl-C presses to actually reach the interruption handler.
What means that you have to memorize a list of "oh, this program needs Ctrl-C 3 times; oh, this program must only receive Ctrl-C once!"... I don't know of any "oh, this program needs Ctrl-C exactly 2 times", but it's an annoying possibility.
Any software I've come across that uses intentional double ctrl-c shows a message after the first ctrl-c. Something to the effect of "shutting down gracefully, press ctrl-c again for immediate shutdown".
Hence you can just press it once and wait half a second, if no message to this effect appears you can spam ctrl-c.
What means that you have to memorize a list of "oh, this program needs Ctrl-C 3 times; oh, this program must only receive Ctrl-C once!"... I don't know of any "oh, this program needs Ctrl-C exactly 2 times", but it's an annoying possibility.