I honestly think the DIS is not representative of reality in this instance.
When I taught (11 years ago) the only end of the year gifts I got were handmade - notes, baked goods, a class project that a room parent finagled, etc. Christmas gifts were the same with a few (maybe 3 or 4 out of a class of 27) store bought gifts. While gifts are nice, I'm very bothered by the idea that gifts for the teacher are becoming the norm (according to the DIS) because it almost seems like tipping IMO.
I am not a gift person and would frankly be very happier to just get a few thank yous from the kids. When my kids were in preschool they gave small gifts, but beyond that they haven't. I spend tons of time volunteering at the school and I make sure my kids are prepared for school each day (homework done etc). A cooperative relationship is worth more to the teachers than any gift could be.
I think people who like Disney tend to be a higher percentage of gift giving personalities. I don't really enjoy giving or receiving gifts, I'm more of a TIME/WORDS person. (I'm thinking of the book "The Five Love languages by Gary Chapman where he describes the five ways of expressing love as words, time, gifts, service, and touch).