People base their opinions off of how much money they make a day. If a person makes too little or too much then to them the economy is "broken".
There has been some failures in the economy (Meepshop!!) that pretty much lowered diamonds to where they stood for months, 400 meebles each. In late 2014-early 2015 prices for winning a CTF game were 15k each to ultimates, with a group of ranked players, I made up to 200k a day. (FYI; money was a lot harder to get then it is now)
Diamonds/diamond armor/tools have risen as much as no one will sell you a diamond pickaxe for 2k. Diamonds are very hard to buy now, and some shops with diamonds selling lower than 600 get the whole server at their pwarp and sell out in minutes. Citizens benefited to when tools were almost worthless, now armor sets can go for up to 8k each.
-- imo, bringing back dungeon would actually add to the economy, more player - player transactions. The price of diamond tools won't fail again because now there is a high demand for diamonds.
The eco isn't broken, it just has too much money in it, and some people control too much of it.
