They couldn't care less about Jon Does "spamming" their mailbox or commenting on Twitter. The FDA's "letter" was a response to increasing questions and pressure built up by MDs such as J.Lalezari.
Rightfully so, they should feel the pressure. Times are changing, they cannot do whatever they want anymore. Until now they were living in past 90s and early 2000s memories. In today's world circumstances have changed. They'll wake up to it eventually, but it won't be a mother's kiss disturbing their sleep.