Simpson's artist Luis Escobar raises this very question on his blog as a way of stimulating discussion amongst the animation community. It's a good point to raise, especially as animated films dominate the box office and CGI is wholly dominant amongst those.
Naturally, the public was aware of the difference back when Toy Story was released. While it was initially hoped that it's groundbreaking nature would be enshrined in the history books by way of its story, thus far, it is its CGI composition that has governed instead.
That was back in a different time though; hand-drawn animation was the dominant form, both popularity and profit-wise. Today, it's the opposite with CGI being dominant and hand-drawn all but eliminated from the mainstream box office.
The point is that with over 10 years of CGI films being released, we're getting to a point where people will soon know of nothing else, and associate 'animation' with 'CGI'. Without some education, there is a real concern that hand-drawn animation may cease to be recognised for its technical merits and instead be judged on the quality of its story or plot.
Further blurring the lines are animated TV shows that, while two dimensional, are CGI insofar as their production through computers and software. Here, the general public has neither want or need to distinguish between traditional and CGI animation.
Should we be concerned that the general public is slowly confining hand-drawn animation to the history books through blatant ignorance? Or does the lack of an ability to distinguish lie at the feet of Toy Story, the film that has set the mould for CGI features for the last 17 years?