Funny how legal experts disagree with you. Directly introducing legislation by China is only allowed for areas that are not within Hong Kong's autonomy, like foreign relations or defense. Article 23 specifically calls for HK to enact the law on its own.
LegCo was nobbled last year. The members representing the majority have no tools in their toolbox to stop bad laws.
The Pan Dems did propose changes to the 2003 attempt but these were ignored.