I feel that Janna has been nerfed way to hard during the big Pre-Season support changes, and now with the current changes that was put up in the pbe will hurt her even more. Janna's a support that gives you a passive and safe laning phase and game in-general. Her damage was never really great, but back in season 3 it was at least some thing and she had the best peeling ability to offer. When Season 4 hits, she was drastically nerfed and now suffers and is very rarely played. About all the changes to the live gameplay...
They stopped her global passive, but made her passive give more movement speed to nearby allies. I felt this was a fair trade off, and I'm happy about this change. Her global passive was a bit ridiculous so it made sense to change it. Her Zephyr and Shield got nerfed and utility buffed and feels that those 2 were some what a fair trade off. However, you drastically butchered her Howling Gate which was practically her main source of actual damage.
Lowering her AP Ratio from 75% to 35%, and then even nerfing the charge up...
Charge Damage Reduced to 15 / 20 / 25 / 30 / 35 (+10% AP) from 25 / 30 / 40 / 50 / 60.
Why can't you make Janna's Howling Gate work like Gragas Barrels? When you reworked Gragas, you lowered the AP Ratio of the barrel to 60% from 90% BUT then make it where it can reach it's old damage and even surpass it if you charge it for X amount of seconds. So Gragas's barrels do more damage if its charged then it did back in the past, and that makes a lot of sense.
Janna on the other hand, had her damage basically reduced so much that if you land a max charge Howling Gate, it deals about the same damage as other supports damage. It's so sad that if you instantly cast your Howling Gate without charges, that it's so weak that Soraka's Starcall is almost stronger then it. If you charge your Howling Gate to the max charge, it's still weaker then Nami's Aqua Prison, Alistar's Headbutt, Blitzcrank's Rocket Grab, and Lulu's Glitterlance. For some thing you have to charge up for 3 seconds and is incredibly hard to land at max charge, it deals less damage then all these supports champions normal ability that they can cast instantly AND Howling Gate has 2x or 3x the mana cost then these abilities. 150 Mana cost for a weak and hard to land Howling Gate that has even less CC then Nami's Aqua Prison....
And about the changes to the pbe...I feel your actually going to nerf Janna even more then buff her with this. It's great that your making the knock up last longer for charging the Howling Gate, however you don't often get that chance to charge it...and then you even nerf her knock up for when you don't charge it. It used to be 0.8 seconds to 1 second, and your making it 0.5 seconds to 1.25 seconds? So now in team fights, when some one jumps on your carries you expect them to rely on a 0.5 second knock up to save their carries? (Of course assuming your ultimate was already used etc). Personally, which how practically weak and almost useless Howling Gate is already, should of kept the original 0.8 seconds as the base knock up and have it increase by 0.2 seconds per second charged. That way it's usefulness stays the same for when you instant cast it, and as you charge it up it will start to increase and max at 1.4 seconds knock up. I mean...it's a 3 second charge and even after all of that...it's still almost 3 times the mana cost, way harder to land, weaker, and less knock up then Nami's Aqua Prison.
Tl:dr: If you want to know why Janna has been barely played lately this season? It's because she's probably the weakest support (damage wise) and she dropped from a great safe and all around support to "highly situational support with very certain team comps" her mana cost are the highest overall in the game with 2x if not 3x the mana cost over all the other supports, her main CC is based off of waiting 3 Seconds to charge it which even after that it's easy to dodge..And if you even land it, it's less damage and less hard CC then the other support's normal skills. Your nerfing her on the pbe by reducing her Howling Gate's instant cast making her peel (Which used to be the best peel in the game) even worse. Now Janna's peel is just ok and not the best (now that Thresh, and Braum offer just as much if not better peel, more damage, tankier, and is a way more aggressive support).
The way Janna is now...Why play her? She has way weaker damage then other supports, she is very passive supports that is suppose to counter all in supports but not any more, now she counters no one. Her peel isn't the best in the game anymore, and with the changes to her pbe she's losing more options for peeling. She can't even safely harass as much as the other traditional supports with having 75 less auto attack range then almost all other supports. Her damage is situational and relies on either landing a 3 second charge up time which sacrifices her main non-ultimate peel, or uses Zephyr which makes her a lot slower. Her mana cost are insane, and all she was compensated was AP scaling Utilities on her skills which most Janna's don't even build AP anyways. Now your forcing people to build AP on her (Which sacrifices the usual good support items that safes their carries) just to be at least remotely close to her power in season 3.
I just feel Janna was nerfed way to hard, and she was my very first champion I bought and my very first main...I'd hate to see this stuff like this continue.