Waaaaay too much in this post to address, so I'll just go with this. BTW, there is a big difference between teasing between friends and complete ridiculing by people you don't even know. If that's not understood, nothing will change your mind on that.
How do you know he hasn't tried to improve his speech? Speech Therapy works great for some, not at all for others. Techniques such as gentle onset, slowed speech, relaxed breathing.....can, in the opinion of the stutterer, make you sound worse then the actual stutter. Even if he did improve his speech through therapy, it can creep back up on you at any moment. Bad days are common, stuttering is never cured, only managed.
The problem with stuttering is it's not fully understood and enough research hasn't been put into it. 100 years ago, you were just considered dumb. 50 years ago it was looked at as a psychological problem. The current school of thought is it is a neurological issue where there is a breakdown between the formation of words in the brain and the vocal chords, or there is an excess of certain chemicals in the brain. People often say slow down, relax....doesn't work that way. People also relate it only to stressful situations and nerves...that's not the cause, it just compounds the underlying issue.
Do you think Lankster choose to have that press conference? I doubt it. The media wanted to speak with him after a good game and a rookie isn't going to say no to the team when being put in that situation. If the media doesn't want to deal with it, they'll stop interviewing him.
I'm not sure how any of us "have to endure (anything) to accommodate a disabled person" in this case, as you put it. How are you accommodating him by listening to an internet posting, that was posted as a form of mockery with little understanding of why he was speaking like that. This is hardly good natured ribbing between friends.