One of the reasons this was done was because Cueball's economy is extremely messed up. People are getting 'rich' way too fast and easily. That is why gold was removed from the shop. Building a single, simple zombie-pigman farm and then being set for life is the opposite of what survival is supposed to be.
Now, the only materials used to buy Grist are diamonds, emeralds, and iron.
"Why is iron so costly?" You may ask. After some research and running statistics, an average 113 iron ingots (13 blocks) could be mined from a single chunk. Iron Golem farms were also included into this and the price was increased to 32 blocks. Now, with the inclusion of the Iron Golem Spawner voting reward, it'll be even easier to get iron (if you win the spawner so try your hardest!)
Having emeralds as a trade creates an incentive for players to create *multiple* farms (which is what we want, more work for your money) to trade materials to villagers in exchange of emeralds. These common materials can include:
Paper (3 sugarcane)
Librarians aren't the only cool villager.
Another reason why the shop's Selling Items were decreased/removed is because this is a survival server. Reliance on the shop should not be occurring; players should be trying to get the materials they need naturally. This is why the Dye and Mob Drop shops were removed.
Spoiler: How to get infinite DyeShow
This post was just to let you all know why certain changes within the shop have been made.