Why does Nid have to be good at jungling

Riot is buffing nid because she is a little weak in the jg right now. WTF is this logic. Nid can play mid or top really well and id say belongs there (could also play support as a non meta pick) but they insist that she should be a good jungler. Nid brings nothing to ganks except a spear from brush and chase potential. Meanwhile I have to stuggle to get through a decent clear on Evelyn who is made to exclusively jg. Or Aatrox who is meant for the top lane but could be a decent jungler with twice the amount of cc as Nid for decent ganks but his kit is so damn weak you cant even play him in top lane let alone jungle.

I dont understand the bias that riot has nor do I understand the forced roles that they try to enforce on certain champs.