Yeah people often get that wrong.
But I'm not sure it's anything to be upset about, if someone wants to show their appreciation of a piece at an obvious pause in the music. But of course more sophisticated listeners understand the difference between the end of a movement, and the end of the complete piece.
At our high school band's concerts, they'll often warn ahead of time if the next piece will have multiple movements, and ask the audience to hold applause until the conductor turns to acknowledge the audience. To me that's a decent way to go about it, for those who actually care about applause between movements.
Oftentimes for our high school band, recordings are in progress either for competition or evaluation, so they prefer to hold applause until the end.
