because "list.pop()"

use case: maintain large ordered list and efficiently remove min item

list.pop() is O(1) but yields the max item.  There is no efficient removal of the min item.

list is by far the fastest collection to use with insort().  While deque offers O(1) popleft(), insort() performance with deque is not acceptable.

Lack of descending support in bisect necessitates workarounds such as using negative-valued items, which hurts code readability and moreover assumes that values are numbers.

Sorry, I don't think this is a worthwhile API extension.  The bisect module is primarily about searching for cut points between ranges.  For your use case, consider using blist or one of the many ordered collection recipes on PyPI (for example: http://www.grantjenks.com/docs/sortedcollections/ ).

If issue4356 is accepted, I think it may be possible to use `key=lambda e: -e`.