General Discussion

One was a strategic error by Biden's team that was appointed by Obama. They waited and let the NRA speak last. While it was important to get multiple viewpoints by letting them be the last up they could see what everyone else had said before considering their statement. In addition the delay allowed the initial shock to wear off and they could see the level of commitment to change.
Thus they came up with the infamous "...Good guy with a gun"

Second was Sen Feinstein undercutting the efforts led by the President and Vice President. Rather than combining efforts she released her own proposal which was essentially a modified version of the 1994 legislation. Not only did this take away from the other actions, it provided grist for the mill of 'they want to ban all guns'.

An opportunity was lost.