So, you want to know why. Ofcourse all of this is for historical reasons, because somebody long ago invented that Ctrl-C should be used to stop programs, and later somebody else thought it was a good idea to use Ctrl-X, -C, -V for cut, copy and paste.
Control-C
Wikipedia wrote:In graphical environments
Ctrl-C was one of a handful of keyboard sequences chosen by the program designers at Xerox PARC to control text editing, with Ctrl-Z (Undo), Ctrl-X (Cut), Ctrl-V (Paste), and Ctrl-P (Print). The first four letters are all located together at the left end of the bottom row of the standard QWERTY keyboard, and P towards the upper right. The equivalent key combination on Mac OS computers is Command-C.
In command-line environments
Control-C as an abort command was popularized by TOPS-20 and TOPS-10 and adopted to other systems including Unix, and Digital Equipment operating systems from which it was copied to CP/M and thus to MS-DOS and Microsoft Windows. In POSIX systems, the sequence causes the active program to receive a SIGINT signal. If the program does not specify how to handle this condition, it is terminated. Typically a program which does handle a SIGINT will still terminate itself, or at least terminate the task running inside it.