With those categorisations a maybe-probably-theoretical-phase-of-the-mooon vulnerability such as CVE-2010-1633 gets put into the same category ("remote information leak") as Heartbleed. This is why severity levels exist.
It's also important to remember that there's a window in which this stuff gets fixed, probably just weeks long, anchored to the announcement of the vulnerability. Once that window passes, any update you're going to see about exploitability is basically going to announce "everyone is now owned". That's a failure of vulnerability scoring!
Your point, however, is well made.