When Kirk gave the 'retard' speech, a lot of people complained about his blatant use of the word 'retard'. But then, I remembered that Kirk was Lincoln Osiris who lived in 1969. A guy in 1969 would not think less than to say the word 'retard'. Kirk was simply talking like a guy who lives in 1969. He wasn't being insulting, he was being in character.
Hmm, that is an interesting take. Though, I always thought it was a satire on how out of touch and insensitive actors, like Kirk, are. It wasn't making fun of the mentally handicapped, but making fun of the type of person who throws the word 'retard' around without care.
Also actors like Speedman, who take on roles like that solely for Oscar Bait and proceed to play an unrealistic (and occasionally offensive) stereotype, thinking that such a role automatically guarantees them an award.