You're arguing a red herring and avoiding what is actually being said with the BSA boxes:  Nothing in there is promoting the preference of the BSA over another similar organization.  Your userbox directly attacks instead of promotes Campfire USA.  Per that policy cited above, the correct way to word your userbox would be "This user supports the programs and policies of Campfire USA."  No injection of political or religious bias, just simply stating that you prefer the programs of Campfire USA.

Read this sentence, and tell me how your userbox DOESN'T violate this:  "Essentially: Express what you like, rather than what you don't like. Express who you are, rather than who you aren't. Express what you do, rather than what you don't."