I think it's so rude to undermine BTS like this. B.A.P. is above them in my list of favorite groups even but BTS has earned their fandom fair and square. I firmly believe they grew because they started to get better in all areas (vocals, dance, rap, and fan service) as well as really start to globalize. If anything helped them it was the amazing marketing. B.A.P. did lose fans because of their hiatus, but it has nothing to do with BTS's growth and to make this correlation is strange. People that like BTS would have liked them whether BAP went on hiatus or not.