This topic has already been previously discussed, and multiple staff have come to the conclusion that it was not such a good idea, without some tweaking of course. For example it could be a special pickaxe only obtainable from legendary crates, of which would also only be able to break spawners that were placed by a player and not spawned in naturally. Overall though, I don't expect to see this change soon. Hopefully they think about this topic while going through ideas of new content involving the next reset.