EG
v0.12 - 4k txsigoplimit 20k blocksigoplimit (under 10 second validation time)
v0.14 - 16k txsigoplimit 80k blocksigoplimit (under 8 minute validation time)
plus other new spam attacks that even carlton banks revealed.
And don't forget the tragedy of the commons:
Removal of Priority Estimation
- ------------------------------
- - Support for "priority" (coin age) transaction sorting for mining is
considered deprecated in Core and will be removed in the next major version.
This is not to be confused with the `prioritisetransaction` RPC which will remain
supported by Core for adding fee deltas to transactions.
Removing coin age priority at this stage will push fees even higher, by causing long term coin holders to compete with the spammers. Perhaps it could be removed in the future in the name of fungibility, but I don't consider it a good idea with the current capacity issues.