The trouble is -- as with any product development -- we don't know exactly what we are going to build because it depends on fickle market sentiments, new technology, etc. That is what sets the upper limit on predictability, and that can be controlled by high level decisions. (Unfortunately, increased predictability usually means decreased profitability.)
That's not enough - you can have pretty good predictability if you know exactly what you're going to build, and if you already built the same kind of thing with the same technologies/tools that you're going to use this time. Which is very often not the case: business very often wants new things that others don't already have, or the technologies/tools from previous times are now outdated (or believed so...).
Scrum is based around this idea, so adopting it (or adopting it better) should be a sign they understand it. If they start saying "oh points are basically time" then you're probably in trouble.
A metric compresses a very rich and nuanced opportunity into a false dichotomy.