Because:
Please riot zyra need a help for survive the season 6 !
Slamurai Jack4 votesIn what universe is Zyra not an early game champion? She's easily among the strongest early game supports in the entire game.
Andrysek571 voteszyra = paper support + big cooldown, zyra have just a good burst zone for 5vs5 (if you do not you shoot one before)
Go play zyra support versus miss fortune and poppy, is just impossible win early except the opponent is really bad
Craft Zeppelin3 votesHow about not buying deadmans plate or ancient coin on zyra and actually buying a sightstone as support.
Andrysek571 votesbecause actually 
> 
GGX Millia2 votesSo?
I will not argue that Zyra right now is not a good champion. But then again, so are a lot of other champions. Every patch Riot changes the balance to keep things dynamic and interesting. Zyra used to be God tier as well (look at the SKT skin she has, she earned it for a good reason), now she's weak, at some point she'll be strong again.
The only thing that actually NEEDS change is her passive which is undoubtedly the worst passive in the game. It must go because it makes no sense. As for other things, some patches will probably change them sooner or later.
Mael bro1 votesZyra is not an end game champion. She's food late game.
Andrysek571 voteszyra late game = monster :)
5050BS1 votesThe problems with Zyra are
Worthless Passive Plant AI that is bugged and has been bugged since her release and Riot has not fixed it E is to slow and roots for to short of time (all other roots are x2 as long and others can root more then one target too) Plants die to quick/easy
If the above was fixed her no mobility would not be an issue because it would balance out her strengths. But as it stands you need A LOT of skill to do good with her and then at that point play another champ and would stomp.