It's because the instructor doesn't ask the student to assess their spacing, or if they do, don't ask them what they are going to do about it if it looks all wrong.
Seriously guys, when someone says "turning base behind the aircraft on ridiculously long final", THERE'S SOMETHING WRONG!
we had to fly massive massive circuits so the neighbours don't cry about it.
F
ck em. They want to buy cheap next to the airport!
How loud is an O-320 at 1000' anyway???
Complaints like that should attract a set of low level circuits!