Edited, to respond more substantively with a quote from your source:
>Linguist George Lakoff has written that the term is a pejorative mainly used by American liberals to refer to people who vote conservative against what liberals assume to be their own interests and assumes they do it because they lack sufficient information. Liberals, he said, attribute the problem in part to deliberate Republican efforts at misinforming voters.
I get your point: condescension against low-information voters doesn't help.
But I think that your argument that the term "low-information" has no use just because it's been used with condescension by some is incorrect.
Instead of wasting cognitive energy of finding a new term for the same exact group of people, I think we should focus on treating them with the respect their sizable number of votes deserve.
The term has nothing to do with enlightenment or even identity politics.