You are right. After one more era they will probably dump it, and this what is happening now is extracting as much money as possible.
But honestly, I play this game more than two and a half years and it somehow became one of my favorite games (with all its shortcomings), and it would be shame to dump it just like that.
On the other hand, there is one aspect of this game that can keep it very much alive, even after no more ages left to explore and build. This is GvG. No more exploring and building after next era, ok. The other aspect of this game is fighting. They could put some efforts in it. One of the ways to do it would be to put some boosts on GvG map for the start (att/def bonuses, expansions bonuses, recruitment bonuses, troops bonuses, goods bonuses, etc). That would attract more guilds to GvG and motivate players to participate more actively.
This would mean that it will be no more building oriented game but more like fighting game.
But as you said, with pink tank boys promoters it is hard to expect this...
I ran off topic, I know, but all this issues like GvG, GBs, diamond prices etc. they are just parts of one big problem, developers attitude to this game.