cause this was originally posted in /pol/ the politicaly incorrect board of 4chan, a place that started of as an ironic "online forum" for jokes and the average internet roleplay of your everyday joe, but at some moment started to atract people that are uninironicaly racist and sexist, as well as some edgy teens that think it's funny to spread the things the racist and sexist members say because "it's just a joke lol". Then we get to the point where the figure of soyjack, the acumulation of everything /pol/ thinks is wrong, was born.
So yea, it's just a strawman for imbeciles and edge teens to keep using to signal someone they don't like.