robust and a better defined extradition law instead of scrapping it.

Two reasons:

1) Hong Kong does NOTwant to become a safe haven for financial criminals and if nothing is done, there will be consequences eventually and  push-backs from China.

2) One of the concerns stated throughout this demonstration is  people are afraid the law would be used to target activists. Well, if that is Beijing's intention it is actually a positive development. At least, when Beijing wants to extradite someone it is out in the open. If you have a robust extradition process and the court rejects the request, Beijing would find it very difficult to snatch that person off the street. Otherwise, Beijing can just kidnap the person and have the person disappear into secret detentions.