"Sion doesn't do high damage anymore"
Then... don't you think you should try a new build?
"Sion gets beat by so many tops"
So, how about you take him jungle?
I do not understand why people are complaining. I never saw Sion in ranked so I can't imagine a terrible number of players had their main ruined by this rework. They changed him a good bit. Don't you think that might change how and where he is played as well?
I like the Sion rework. I actually enjoy him now. I take him jungle and build Quill coat > Frozen Heart (if ad heavy) > Golem > Mercy treads > Hydra (only real damage item you will need) and by that time my team has won. Sure, you don't do a lot of damage with this build but you can zone and tank like a boss while your team kills the enemy. People say that Sion's new ult can't keep his team alive like the old ult. Bullshit bud. Build tank, smash their key targets (if you can) with his ult before your team gets there, pop shield and charge your Q to knock the enemy up >>This does not mean fully charge your Q... Just charge it so it knocks them up<<. With that you have stunned, knocked up, and done a damn decent chunk of AoE damage and the enemy will try to burn you down as your team catches up. This is why you build tank. Enemy wastes so much on you while you zone their carries and your carries shred the enemy team.
TL:DR Sion has changed. With this change his playstyle, builds and place on the map will have to change with him.