If posts like these are acceptable, than that statement is patently false, and should be changed. If it is not false, then posts like this are inappropriate on main.

What does the description "is acceptable" refer to? Acceptable by what criterion? The real question is whether things like this should be encouraged or discouraged, using whatever methods are at our disposal, including establishing a policy for moving "off-topic" posts out of Main. Instead, you seem to be appealing to an existing social attitude, which shouldn't be a major factor, as it too can be influenced by good arguments and other means.