over time, this has certainly been the reason to dislike this kind of item.
this was especially true when grinding for resources for a singular item is the end game content, or it is a necessity before you can pursue harder end game content.
However, I have no issue with things like the siren ring or DISC belt, or reshii wraps or things like this.
there is very little grind to any of these things and the benefit for working towards them has benefits for the most of the duration of a patch or even across patches.
the other idea of a singular piece gear giving having significant impacts on game play (versus designing your talent tree in a particular way) is that I think it is much easier for blizz to balance a cloak, ring or trinket rather than having to redesign a talent tree.
the downside, of course, is when the item goes away, the power goes away.
some of these “borrowed” powers have found their way into talent trees over the years.
however, there are some items that are just so good that when they go away, they can change how you play. as a tank, I think of Fyrakk’s tainted rageheart, or the chromebustible bomb suit, as trinkets that can really enhance your play and you really miss them when they are gone because there is nothing similar in the tree to replace them.