My friend is an ARMY and kept going on about how BTS isn't kpop and she hates all other kpop groups. So I told her BTS is kpop because they sing in Korean. She said she knew that BTS is kpop, she isn't that dumb and that ARMYs know that BTS is kpop but choose not to call BTS kpop. This is because other fandoms had said that BTS wasn't kpop first in order to exclude them in some way (I wonder why ). So, ARMYs decided to take it literally and say that BTS isn't kpop. It's more of an inside joke than anything. I feel kind of dumb for calling them out now.