The problem is the interface for this.  A single drop-down list.  In many places in Wikidata, like constraint adding, a 2 level list would be amazing.
The single drop-down list for suggestions is very 1990's and there are widgets for listing suggestions that are much smarter and more helpful.
Here, a filtering mechanism within it would be better where the user sees the 1st level scrollable listing and click selects on a high level category... for example, "TIME" or "MOST USED" and then sees a 2nd level narrower scrollable listing show to the right.
I'd rather see resources and budget put into developing smarter hierarchical or categorical listing widget for suggestions.
Let's leap from 1994 to 2018