That Helen Keller was a socialist doesn't mean much, so I can see it being omitted.
But, then again, if you're presenting her story as one of inspiration, and simultaneously want to instill a sense of nationalism in your students, you leave out the part about her being socialist so the kids don't develop a liking for that system.
The hardest job of a historian is to select what to omit, since there is a virtual infinity of information available. Those who have some axe to grind, of course, want the stuff that supports their view to be included, and tend to paranoid reactions if it isn't.
I dare say all school systems have an understandable tendency to glorify their country, and I am not sure, so long as honesty is maintained, that this is such a bad thing. We should be proud of our native country -- it is a natural instinct and, so long as it doesn't become jingoism, I think it is healthy as it serves to motivate work to improve ones homeland.
Well, that's not the sense I got in school. I don't mind others being proud of their countries, nor do I necessarily mind that being taught (though I'm not much of a patriot, myself), but our faults should be addressed, at the same time, and they're often not. America is presented as basically some kind of torch-bearing messiah. Sure, that might have been the case 200 years ago, but it's not anymore.
Socialism is state ownership of business activity; Communism is common ownership of business activity. Since the transition to common ownership would logically require a period of state ownership, the two are easily confused.
Gotcha.