No the problem was that the sticker singled out the theory of evolution without explaining why. The movement that singles out evoltution for opposition is historically religious. So people put two and two together, regarding the sticker as an attack on evolution for religious reasons, and not for scientific reasons.
If the sticker had said "ALL scientific theories should be considered with an open mind..", etc, etc then it would have been okay. But the people who drafted the sticker only wanted to cast doubt on evolution.
Evolution is a unifying theory with many gaps in the puzzle ("the missing link", maybe you've heard of it). Not so other theories.
The movement that singles out abortion for opposition is historically religious as well. Does this mean that any dispute over the origin of life (when does life begin) automatically require that schools deny life begins at conception? There is plenty of bad science being pushed (a fetus is not "alive" is one example).
I have said that I am not for teaching creationism in schools. I would also want any teaching of the Big Bang and evolution preceeded by an explanation that they are theories that are works in progress, some new details will be learned and some old beliefs will be disproven (corrected in the revision). It is a "leading edge" of science as is medical research; should we be teaching that chemical X is a cure for AIDS, cancer, heart disease, etc. or let kids do their own research into the matter on their own time?
We hear how some students after 1969 still had textbooks that said "we may one day go to the moon...". Would we want to teach a theory in progress such that some generations are taught outmoded concepts?
As I say, man began "somewhere" but scientists do not agree on which continent. Read a book on you own time if you want to discover the origins of man with no "grey areas". I have no problem with presenting the biological record (this was found here in this era, this was found here....). Stringing along such concepts (and even saying "these people came from here TO here...) is where a more educated "guess" is made (and sometimes it is wrong). Teach fact, not speculation (or at least identify speculation as a theory in progress).
I also brought "man made" global warming into the discussion. It is relevant because some people are letting their agenda bias their interpretation of findings. Schools do discuss this topic and again, it needs to be exposed as a theory at best (or possibly even an "accusation").