There was a time when land space was getting to capacity for the game and to solve that problem INNO introduced AWs to make a player be able to pack more power into less space and be able to have a smaller city layouts because they were at their limits of how many expansions they could add to the game.
This is completely not true. There were plenty of premium expansions and a whole lot of the grid (not map) left to grow into when AWs were introduced.
It is true that for years Inno worked hard on encouraging players to place and upgrade AWs. I enjoyed keeping my goal to have all AWs for years. My play style has a bunch of aspects geared toward upgrading AWs. Things like daily map visits to buy KP daily, saving event currency for AW instant days, pushing higher in the tournament solely for the purpose of gaining more KP, keeping scouting going at all times for even that small amount of KP to name a few. Then is the matter of space. There is NEVER enough space in any city builder game. Those of us who could instantly purchased premium expansions when they were released. Partly, that was so we had room for all those AW.
This is the progression I saw as I watched top players I have known over the years leave the game.
1. The Spire was introduced. Those who were tournament beasts now had to adjust to another drain in troops. There were a lot who pushed hard to upgrade battle related AW, like me, although I was never a tournament beast.
2. Some of us decided to cater the Spire to save on troops but that takes more space for factories to add needed production.
3. Then they decided, after all those years of playing the game the way Inno very clearly stated and encouraged, to turn much of what we had built against us with the big difficulty calculation changes.
4. Now a whole lot of investment in time, effort and $$ became liabilities instead of the advantages we had worked for and spent real $$ to gain.
5. Besides this causing a whole lot of ill will toward the game, now completing the Spire to the top and making a respectable showing for a top level player became a job instead of a game. In my own case, it meant that the work I had done since the Spire was introduced to level up my battle related AWs so that I could climb the Spire and up my tournament scores was not only wiped out but also counted against me. So, I just gave up and do what I am comfortable with given my reduced abilities.
6. It became very clear that to even keep our cities performing at the level we were used to we would have to spend even more real $$. That was the straw that broke the camel's back. I am talking about top players who were, and had been for a long time, big spenders.
7. In the end, we are/were working what felt like a job but we were paying Inno more to do that job. So, I watched top players I had played this game with for years leave the game. It really has been a sad turn of events.