Normally I'm of the opinion that, if even just one or two people have the same problem with a UI, it's probably worth considering a valid, addressable problem,

Normally I'm of the opinion that, if even just one or two people have the same problem with a UI, it's probably worth considering a valid, addressable problem, no matter how much it seems like the user's "fault", but even I'm having trouble rationalizing this one. May I suggest that maybe you're having this thought because, intellectually, you know how disabled fields are frequently styled, however, in natural conditions, you probably wouldn't actually make that assumption unless not all of the fields were styled that way?