I am both a science teacher AND a parent, so I can come at this from both perspectives. As a science teacher, I was given a budget of $250 last year. From this, I was expected to purchase all lab supplies, resources, and copy paper. Yes, COPY PAPER is not supplied by the school. Since I'd prefer to spend my meager budget on science supplies, I add 2 reams of copy paper to each student's supply list. Do parents get annoyed by this? Probably. But after spending $750 of my own money on my classroom last year, I don't really have a choice.
Previously, I taught in a Title I middle school with 94% free and reduced lunch and a majority non-English speaking population. We didn't even bother with a school supply list, as most of the kids wouldn't show up with anything - much less a graphing calculator and a jump drive! Instead, we had a room on the first floor dedicated to school supplies purchased by the district for the kids. When those ran out, I had to buy pencils/paper for my own classroom out of my pocket. We tried putting responsibility on the kids to bring their own things when supplies ran low, but few of them cared. If we didn't supply the pencils, etc., the kids would just sit in class and do nothing or cause trouble - far worse than buying $50 worth of pencils for the year. It's a no-win situation for the teacher.
As a parent, I recently spent $60 on supplies for my 1st grader. I'm okay with it, because I know the teachers have little money to work with - and lots of kids probably won't come to school with anything. This gets me upset with other PARENTS, but not the teachers. Educators are forced to deal with small classroom budgets, kids who come to school having not eaten dinner the previous night (but sporting the latest in Nike fashion and carrying a cell phone), apathetic parents, intense pressure to get students with IQs below the 10th percentile to pass proficiency exams, kids who are socially promoted to high school despite not being able to read above a 3rd grade level, gang violence in the hallways, drug use on the playgrounds, and on and on. If your schools are asking you to purchase items like calculators and jump drives, be happy you live in a district where most people can and will actually buy this stuff. It means your kids are probably going to school in a pretty decent place.
IMHO, a school supply list should really be the least of our concerns in this country.