I read this and hear this excuse from time to time. It usually happens when I draw people’s attention to Bad Stuff that is going on around them, sometimes right under their nose.
The frustrating aspect of the response is that it is often the response they give when you point out to them that their opinion and/or understanding of the issues or events is, to put it mildly, deficient. Since I normally move to argument supported by facts, it probably occurs to them that I might actually (at the very least) know more than they do about the topic. (Whether I know enough or have the right knowledge is a whole different question).
The tart response that I want to use, but (to be truthful I seldom do use) is “well then it’s about time you woke up and started paying attention”.
The reason I seldom use the response is that it is, most of the time, not likely to yield a positive outcome. Nobody likes being told that they have not been paying attention. Especially if they haven’t.
So I usually count to a large number and move on. But the sentiment remains. If you want to have serious opinions that you can support and hold a discussion on, it might be a good idea to, you know, do some work in advance.