I would like to say I understand where you all are coming from with this. I understand that humans have a range of behavior, and we're all beautiful and children of the universe.
...
If you have a person, who consistently acts like a petulant child even though petulance falls completely within the spectrum of human behavior, I personally, and maybe I'm completely unreasonable in my expectations(!!!), I expect a person to act like a mature and reasonable adult.
Like you, I don't think these truths are mutually exclusive.
I worked with someone for years who had Asperger's or some form of autism.
She was a wonderful woman in many ways. She was one person who would always send Christmas cards to her coworkers, with handwritten notes, and she had a child with many physical and mental difficulties who took a lot of care, yet she was tirelessly his sole defender and passionately loved him. She was also meticulous and very intelligent, a wonderful analyst.
At the same time, she was just one of the most difficult people I have ever worked with, and her presence in the department was more disruptive than anyone I have worked with in my entire professional career. Just because she had many good traits and was doing the best that she could did not resolve the office interpersonal difficulties. It took a few years, but her effectiveness as an employee was greatly reduced because none of the project groups wanted her working on their team -- she was inflexible, vocally critical, paranoid, used inappropriate language when upset, and simply would refuse to do the tasks she was assigned in a way that integrated with the goal the team needed to accomplish. She also had little sense of boundaries or appropriate behavior in a community setting. She would act inappropriately in front of the customer, which threatened our retention of work contracts; at least one company said they did not want her to participate in any more meetings, or else...
Morale suffered when she was involved in a project because progress would inevitably be derailed; things would take 2-3x longer to accomplish, and often her portion of the tasks would have to be redone.
I attributed a lot of this to her condition, which wasn't her fault; but it didn't change the fact that she was a hindrance to an effective workforce and was causing the bulk of other employees to either transfer or leave because of their own diminished effectiveness.
How did the company first try to deal with things? By accepting her as-is and trying to turn a blind eye to her influence. This was entirely ineffective, degraded morale, and built resentment, even among mature employees who were duly taxed by their dealings with her.
In the end, she got herself fired when a consultant was upgrading the office systems and did not handle the backup process exactly how she felt he should have handled it. I was sitting in the cube next to her and it freaked me out -- she became verbally abusive and no matter how professionally the consultant tried to handle things and resolve the issue (I was listening and was amazed at his patience), she began shouting out strings of obscenities and finally began throwing things at him, one of them being one of the heavy paperweight-style staplers that shook the cubicle wall when it hit. (her aim apparently sucked, thank God.)
The consultant was smart and left and reported the incident to HR; the next morning she was gone.
I find myself torn in situations like this. Obviously we are all different, as is she; and you want to be as accepting as possible and embracing diversity, as well as being understanding of particular personal issues that have difficulty changing. At the same time, when someone is a disruptive and demoralizing influence, just turning a "blind eye" is not going to work and in fact seems to exacerbate the difficulty.
I'm not sure how to resolve such a problem in a way that honors everyone or makes the most sense in terms of company productivity and efficiency.