You want an active ladder but : Why do you think people play arenas ?

If you don't have any goals to reach, you have no reason to play the game.
Look at any MMO game, the community is increasing when there is something to achieved, it is most often ladder and rewards or social interraction if the game is good. Also, a lot of ppl "follow" when they see somethign interresting/challenging

Conclusions :
- If you want more ppl to play (1800 or not) you need to make the game balanced and competitive ... Almost everytime i see motivated players, thats because they realized how its fun to play better the game by watching higher rated ones, not because they want to smash swifty macro.
- Farming your s8 gear with arena reqs is maybe a plus but look at CSGO, everyone has the same potential of killing, bronze or globals
- Need to remove toxic players & cheaters faster
Spot on. Seasex for president.