This isn't an acceptable response in my opinion. Better to call them out and have them answer for their actions, especially considering his husband suggested he was going to do so (then tried to deny he stated this on twitter). Giving fake reviews isn't an honest response and only drags one down to their level, furthermore it is bringing their book far more attention. Free advertising for others to go out and buy the book just to spite Conservatives.
Their actions are just in a long line from the left. Michael Moore telling people to protest outside Trumps inaugeration, others claiming that he is not their president, not legitimate, sanctuary cities stating they will not help deport illegal immigrants (themselves openly breaking the law). Quite frankly, the more the far left express themselves the more the rest of the nation realises how unreasonable and radical they are. Appears to me this is becoming a National Security risk.