When working on a spawner acquisition system, I discovered that non-opped players would always get a pig spawner when they placed the item. As I had no problems, I deduced that BlockEntityTags were blocked (probably intentionally) for ordinary players.
This throws a really bothersome block in the way of many item systems, and I request that it be reinstated. If that is not possible to do, at least tell me the reason.
Intended for security reasons.