Your observation is valid, but there can sometimes be quite a bit of angst and suffering in this process, both when parents choose not to pass on heritage langu

Your observation is valid, but there can sometimes be quite a bit of angst and suffering in this process, both when parents choose not to pass on heritage languages (that their children wish had been passed on) and when children choose not to speak heritage languages (that their parents wish they'd continued to speak). I've experienced this within my own family and heard about it very often in other families -- even where the languages in question aren't endangered in the least! Sometimes the parents or children involved found this to be quite a hard and quite a stressful decision, and the people on the other side of the generation gap don't always feel entirely comfortable with the decision. But you're right to point out that this doesn't have to involve any sort of coercion or compulsion; it's often just people making choices about what they think is best for their own families at a given point in time.