I totally agree. I understand why he removed it, but we haven't had a new ore in over a year, and even it doesn't do much.
This game is called MINEcraft, mining from the start was a decent part of the game. Mining is a big deal, and it still is, but eventually, you get to the stage I'm at. You never mine anymore, you just don't, because there's nothing left to mine. I have so many diamonds, and so much gold, iron, redstone, and lapis that I never mine anymore. There needs to be new ores that add content to the game.
tl;dr: Bring back emerald ore, but if you don't want it to be used for trading then just give it some new uses.
This ore is amazing. If you think about it, Minecraft is already a wonderful game but with emerald ore as a currency system with villagers, Minecraft becomes more than just a video game. With a new connection with villagers, Minecraft becomes also a world with an economy.
They need to bring back what was wished for.
And make it less biome specific.
When I don't see any npc villages in sight, and want emerald blocks, I don't really want to migrate who-knows-how-many miles to an npc village. I'd rather mine in that situation.