Comment 6 for bug 1375028

Right, it was off by default at some point. If you upgraded through multiple Ubuntu releases it might have been stuck off from that time. That's a problem. It's quite possible that the other solutions were still working back then, so you didn't immediately realize it.
A warning would have to pop up on startup too and that's something we try to avoid. Also I'd rather keep references to specific desktop environments to a minimum. I think the time would be better spent updating the raise-over-dash code one more time. I'll see if I can get it working, that'll buy us some more time.