"We're going insane as a country"

Friend while I think you are close to the truth you are mis-characterizing what is actually going on. What is happening is not insanity but rather the consequence of decades of contextual control both socially and through popular forms of media. What I mean by that is not that someone says it isn't ok to say or express an idea, but rather that the prevailing context into which it is admitted causes the success or failure of the idea. People inherently appeal to the overriding context present instead of concerning themselves with the idea itself.

Let me give you two quick examples. Let's say that you and I decide to order a pizza, and we will choose the toppings for each half, but also have some vested interest in trying what the other person chooses. I say that I want to choose pineapple as part of my half. The immediate reaction from many people is to dismiss that topping choice and then start going into a pre-conceived routine about pineapple on pizza. What is happening here? The person may not even especially care about pineapple on a pizza but they are appealing to the created context in which "pineapple on pizza is bad." The content isn't controlled, but there's no real thought going into the exchange, because even if both people like pineapple, there still remains "why don't people think it is awesome?" -- the context remains overriding.

Let me give another example, a stronger one: Let's say that we both watch the Star Wars film, and I find it to be mediocre but entertaining. The context here is that there is a "consensus" among a majority which says that opinion isn't correct. Therefore, even if my opinion is taken seriously and not dismissed as "trolling", it falls within the prevailing context to such a degree that the opinion appears to be there simply to disagree with the prevailing context, and already it has lost merit as its own concept.

When you say "we're going insane as a country" then, you mean that there is a strong context of "being PC" as most people would describe it. Even that is not a great characterization of it. There's no political drive for the common person, they aren't "being PC". Rather, they are attempting to uphold the created context of information. People do this for many reasons, some don't think about it and accept the overriding context as important, some do so in order to "get along" with other people and then of course you have others who take an opposite stance to fulfill some sense of individuality. However, being for or against any idea presented within this architecture is inherently meaningless as the response is already dictated. Even as you read this (if you are still reading this) there is a desire to bring the context to this, does the person who's writing I'm reading mean that they want this to happen, or maybe they are pro-this or anti-that. There is a hypnosis in the desire to frame ideas in some relevant context so that they can be dismissed or approved of.

Ultimately then, when you say that "we are going insane" or that people are being "too PC", or as the OP phrased it "in our quest to be tolerant." There is an underlying lack of thought in terms of what this means. It frames the actions in question as being part of this "quest" and then this response and the responses of the thread are merely part of that system of responses. The inherent context is already framed for both the initial reaction and the discussion. "Being offended is bad" brings about the removal of some object in a room, and "Attempting to prevent offense should have a limit" is the one for the discussion. Nothing moves beyond that and nothing is said, despite any grandiose support or rejection the context isn't changed no matter how much content is produced for either side.

Ideas are no longer considered based on their merits and value but rather on their relevance and appeal.