Glad to see a portion of the letter we wrote back in 2013 re-posted in this thread.
I would like to opine that the dialog and subsequent debate today is much, much different than that in response to the Sandy Hook shooting that precipitated the letter in 2013. Look carefully at the points we raised. These are exactly the major points being discussed and appear to be becoming a consensus of the majority of the talking points that are gaining traction.
Can I prove that there is a direct cause and effect relationship? No.
But I can say the letter has been "quietly" distributed very broadly. Has it influenced the thinking and the subsequent discussion today? Maybe so.
That my friends is the MO of the "Quiet Professionals" and this is a typical outcome.
Plant some simple truth seeds, tend the garden, be diligent, and patient. Usually, the efforts will bear fruit.