Are Reasonable Observers Unreasonably Reasonable

I like to refer to the "Reasonable Person" in tort law as the "Unreasonably Reasonable Reasonable Person," because no one I have ever met is as careful and prudent and reasonable as the Reasonable Person (thus, he/she is "unreasonably reasonable" the kind of person who sets the alarm for 3 am to get up and shovel the snow off the sidewalk to protect pedestrians against foreseeable risk of harm).

Is Justice O'Connor's reasonable observer "reasonable" or "unreasonably reasonable." Is it reasonable to perceive a Nativity display in a public park during the Christmas season as an attack on non-Christians? Does anyone really think that the city government is saying "non-Christians are second class citizens" when it puts up a Nativity display or a Ten Commandments display in the public square? Why not view the Court's cleansing of religion from the public square (a public square that includes all sorts of secular holiday displays) as an endorsement by the Court of the message of hostility that religious subgroups are not full members of the political community?

Does the endorsement test as applied by the Court violate itself?