People argue their case like adults all of the time, the problem is that some people don't like the arguments that are being made. Argue your case like an adult...but you can't use the following arguments: X, Y, Z. Well, if they can't use Arguments X, Y, Z then it seems like they're being asked to abide by some unspoken PC code.
You posted a wonderful diatribe but it completely sidestepped my point.
Only one side has an issue with PC speech. The side that is against PC speech shouldn't have a problem with the race card or with calling people Nazie regularly. They shouldn't have a problem with any language used in the public space. Asking any group to change how they about any subject is asking them to be PC.
A person cannot be against society becoming too PC and also upset about society's use of language directed against their preferred group.
Here's a simple example to help you stay on track. "Muslims are terrorists and can't be trusted." says Person X. When told that the statement is xenophobic, Person X says that it's the truth and the PC police are going overboard. When Person Y calls Person X a "racist", Person X says "Why do you call everyone racist, you shouldn't speak that way."
Person X doesn't see that the request for less volatile language contradicts the previous desire to express volatile language. Person X abhors the PC code when it restricts Person X's speech but implicitly appeals to it when the speech is directed at Person X.
That is the point that I am making.