Why is Bollywood remaking so many old movies and songs?

I really don't understand why is Bollywood coming up with so many remakes of old movies and songs and they are legit spoiling it to a whole new level. I feel they're definitely falling short of good scripts and creativity. Another reason could be that they want to target the younger audience by remaking classics or coming up with song remixes which are usually fast paced. The music composers these days can't come up with original songs they just pick on the old ones and add new beats and tones here and there. I really think they should leave the classics untouched! What do you guys think?