I still don't agree Dan, the poster is using a subtle shock tactic to make you think, and obviously it worked, as regardless of what you think or beleive, or wether you choose to wear a poppy or not, someone was moved enough one way or the other to copy and paste the poster onto a well subscribed forum, and then get themselves into a full on debate over it, you have still donated, and raised their profile without realising it.
Regardless of how any of us think you yourself have also said through your own fundraising efforts how hard it was to get people to part with their money. not those words exactly before you start jumping up and down but with inferences to the lack of donations from w'brs,
Maybe you should have gotten in touch with the RBL and asked them who designs their posters and get them to knock one up for you, as i for one had no idea what you yourself were up to, If I had then I would quite happily of supported you if it were a worthy cause.