What's wrong with older main protagonist?

[Star_Of_Hope]

Hm.. age shape personality, interesting, this could be one of the reasons too

Yes.
They are not reckless and they do things rationally

 

[Blackangel]

It really is, only one or two title of mainstream anime had adult main protagonist, the rest is just teen

i agree with that
i am not surprised to see teen main protagonists in most of the anime. it's cool

 

[Demon_skeith]

I think they are just trying to keep it to what the younger audience may like more. To me, I wouldn't mind some older people taking charge.

 

[Silver_Fox]

I think they are just trying to keep it to what the younger audience may like more. To me, I wouldn't mind some older people taking charge.

Okay, so demographic reason