It's hard to diagnose a dead guy with no history of mental illness. And I didn't cherry pick those two. They are literally the two deadliest mass shooters in our history.
I like the idea of better mental health care. I'd like to think everyone does. The 21st Century Cures Act passed the Senate in 2016 with 5 nays. That was the last major mental health law passed by our government. And since then we've had a guy kill 60 people in Las Vegas, someone kill 23 people at a fucking Walmart in El Paso, a 19-year old kill 17 people at a high school in Florida, etc etc etc. But we should probably just pass some more mental health legislation, right?
I agree with you that this proposed tax on already legally owned assault weapons is ridiculous. Deep down I think Joe Biden does too. It's going to be the first thing that gets bargained out if anything like his plan gets introduced in congress. But is doing nothing really the best option here? What is so wrong about putting a tax on transfers or registering guns? That criminalizes literally no one.