Why do guys who had long hair get their hair cut in the music industry?

I've noticed that alot of singers and rappers who use to have long hair in their early stages and later on they end up cutting their hair and wearing two earings in their ears, what's up with that can somebody explain that 2 me? I shall post pictures of examples so you all can get a visual o what i'm talking about.

Roc Royal from Mindless Behavior

Before his hair cut

And after, why did he cut his hair, he looked so cute with the puff?

Bow wow wit his hair when he was young or shud i say Lil bow wow

 
 And dis is bow wow now...why he got his hair cut???

Omarion Grandberry with long hair from B2k

To the right is Omarion with his hair cut

Lil Fizz or Fizz from B2k with his twists, long hair, puff and ponytail (such a cutie)

And this is how he looks now, i dont care for this look but he has great hair

Ludacris wit his afro and braids

And him now, wats up wit dat hair on his cheek lookin all slick?

Abraheim Mustafa aka "Arab" from SODMG

And here is arab wit his hair cut

So yea these are just sum examples of boyz and men who had long hair but now have got it cut. All i wanna know is why? What do you guys think?