Not at all. Decode performance is generally a very important consideration, as it has to go in all kinds of devices. Unbounded decoding time would be terrible (

Not at all. Decode performance is generally a very important consideration, as it has to go in all kinds of devices. Unbounded decoding time would be terrible (it would "lock up" embedded devices), and it's almost certainly an oversight. You probably have encoding performance in mind, where there's much more liberty to make things very heavy.