because the happy pop music sells. and JE loves the $$$.
their debut single only sold 100k.
but "Sukiyanen, Osaka" was the turning point and we see the sales they get today because of that.
i kinda wish they went back to their enka/traditional roots though. at least for album tracks or something. BECAUSE "NANIWA IROHA BUSHI" WAS AMAZING. i love it.