I think we’ve been pretty up-front about that a number of times since it was implemented 15-18 months ago.
Usually you don’t even notice this behavior kicking in though… it was mainly included to stop unpleasant amounts of extra turns happening when a troop/board started looping, and seldom kicked in until at least 3-5 extra turns had been obtained.
After we re-balanced the number of gems created during gem-spam to not scale off magic, it became quite rare in fact.
I think it was only when the bug was introduced a few days ago that it became really noticeable again. And we’ve toned that right down again now, so it should be close to where it was before.