Heresy in League of Legends is contained in the words ranged top-laner. Akshan has been played in the top-lane for some time now, harassing everything into oblivion with a very safe lane from ganks. Riot intend to rectify that.
Though there are many reasons Teemo is hated by the entire League of Legends community, the main one is the fact that he is a ranged top-lane pick. The same goes for Quinn, a champion that makes the lane unplayable, not just in the top-lane, but everywhere else as well, with her roams.
However, both of these champions have been designed to do exactly this. Akshan was not. Not only is he a nightmare to play into, the new meta of Akshan top that has been established by the player-base is also a coin-flip for allies as well, as you immediately lack a frontline engage, and need Akshan to win his lane, to make up for that fact.
In patch 12.3 Akshan's passive is getting nerfed, with a lesser movement speed bonus on canceling his second shot, nerfed to 20-75 from 35-75, and weaker scaling on his three-stack bonus magic damage, with it being nerfed from 20-175 to 10-165.
The statement Riot Games have given regarding these changes is:
"Akshan's been quite strong everywhere (especially in top lane), so we're hitting his early passive power to make his harass on melee enemies a bit less dirty."
This way, Akshan's lane opponents will not be harassed so easily in lane, and fighters who can take the fight to Akshan will be capable of doing so, as his kiting potential will be diminished.