ck1 - people who tend to regard the sensitivitiy of others as 'ridiculous' or 'over the top', or even the good old 'political correctness gone mad' are invariably those who are utterly untouched by the affects that such issues have on some people.
I speak as someone who does suffer from mental illness, and although I do not find myself feeling abused or in any way connected with the images perpetuated by these costumes, i do feel the need to step up for my fellow sufferers whose sensitivities are invaded by this sort of blanket 'humourous' sterotyping.
I try hard to empathise with anyone who feels themselves put out by the thoughtless actions of others - be those issues large or small - and i think that to simply dismiss such feelings as of no consequence simply because you are not involved, shows a a degree of insensitivity which I am sure you do not possess - but then, we are all seen as others see us - including the mentally ill.