Disabling auto complete is something I’ll do for credit card info, etc.
For names and such, disabling auto correction is something you might want to do.
The only reason I see to disable auto capitalize anywhere at all is when you have a case sensitive input field. This will, in most cases at least, have to be case transformed on the backend anyways, to take care of weird user input. I can only see that disturb a user where the input can be both lower and upper cased and should not be altered by the application in any way, shape or form. This boils down to stuff like product keys, as Christian pointed out.
Not to be negative or anything, but Chris would’ve made a list with do’s and don’ts for each feature, I guess. Chris being Chris Coyier ;-)
]]>