It's sad. The game was presumably healthy about 18 months-2 years ago. I know, for myself, I contribute a few bucks regularly if a game is fun and fair. Slowly every aspect of Dragon Story was changed over this time in order to try and squeeze gold at the expense of what made the game fun. I think we all get it...they have to make money somehow but there has to be a balance. People aren't going to put thousands of dollars into a game like this like they would in something like Star Wars Galaxy of Heroes or similar. The mistake was made in trying to follow that same business model with this game. Result... you turn too many people off...and the player who puts in a few bucks from time to time in is far more more important in this game. Many just won't come back when things turn as unfair as they have.
I don't think you can treat a game like this the same way as a more competitive game in terms of what the impetus is for someone to make a transaction. Over**** on events and new dragons puts people off. Changing percentages during events/bingo for breeding/battling puts people off. A lot of companies like to throw around the phrase "confirmation bias" when players see a clear change in percentages that would benefit the developer, but it's not. It's insulting when this has been tracked over long periods of time and the evidence is there.
I don't know. Maybe all this will change for the better at some point. Just hope it's not too late.