Presumably because the programmer likes that element of western culture. Are programmers supposed to conduct a poll among global stakeholders before they implement an easter egg?
This reminds me some review or article i read many years ago about OS/2 2.0 (the one before Warp) that wrote something along the lines of IBM tried to use a color palette that would be appropriate for all cultures around the world and ended up making a user interface with colors that looked very bland for everyone :-P