So I'm a little torn on this issue, as I can easily see both sides.
On the one hand, like many others I'm one of those people who bought Elite primarily for spawner mining. I'm definitely empathetic towards those who did so and are now upset that it's been removed.
And, to be fair about the economy, spawners create a different economy altogether through the fact that they can be bought and sold. If you mined a spawner in the wild, you could sell it to someone in Towny to use for their grinder or even use it yourself.
Not to mention the fact that having this as a perk will lead to many more people buying Elite+ ranks because they want to mine spawners.
In general, as a personal note, I also felt that mining spawners was a big draw to keeping me on the server anyways. It felt relatively unique and was something that set Meep apart.
But the suggestion isn't flawless.
creat[e] too much supply compared to the demand of many items (virtually all mob drops, plants via bonemeal, food and wool via cow and sheep spawners, furnace fuel via blaze spawners, etc). This creates a flooded economy where resources basically have no value
~ @Zebo616
This is the truth - spawners utterly decimated any economy for bones, arrows, spider eyes, rotten flesh, string, etc. Any and all mob drops were incredibly common and anything made from them was too.
To a lesser extent, there's the issue of XP, though unlike a lot of people I'm not going to fool myself into thinking that the market for XP and XP related items will ever be incredible, as we still have grinders despite the limits. It will still decrease the prices of enchanted items though, as spawners do make XP inevitably easier to get.
Finally, there's the issue of EULA compliance. The server was almost shut down a while back, and Fuzzlr had to remove a bunch of perks. To be fair, since /fly is back somewhat, it may have been lifted slightly, but if spawner mining does come back it might end up having to be something for all players rather than just Elite+.
I do have a couple suggestions to combat the economy thing, though, and the main one is not adding back /spawner and perhaps making all spawners drop as spider or zombie (maybe even just spider, since zombie's rarely drop iron, carrots, etc.) This would prevent the sheer amount of mob drops that flooded the economy in the past, since spider drops in particular are relatively useless and extremely common, while rotten flesh is also pretty useless.
More mobs could be added to the list at staff's discretion such as pig, sheep, cow, and chicken, since food economy is trashed already.
This reminds me of a bug a couple years back where all spawners turned into pig spawners, which could become an intentional thing.
So honestly in the end I'm a +/-. I think it's not the inherently negative thing that a lot of people think it is, but it's also not all that positive for the server. I think it's up to staff discretion at this point if they think they can implement it in a way that preserves the economy and is EULA compliant.