I've not really come across white poppies before, but I've had a look and they've been around officially since the 1930s, originally intended to be an anti-war statement.
However, the British Legion has this to say:
"There is no message of glorification. What you wear is a matter of choice, the Legion doesn't have a problem whether you wear a red one or a white one, both or none at all. It is up to you. We don't comment on matters spiritual, poppies are there for the benefit of the living."
So as a neutral in this debate; why do people feel the need to be outraged/offended by something that the British Legion aren't bothered about?
Stan's picture was showing the white poppy complementing the red poppy, not replacing. I'm sure someone will explain further but from what I can see, it wasn't necessarily disrespectful per se, unless the intention was there to disrespect.
From what I can tell, its a media led dislike campaign.