I personally find these things unnecessary because we already have guidance and commentaries on the Scriptures from the Church Fathers like St. John Chrysostom's homilies for example. And if we need help understanding them, then I see no reason why we cannot just ask for guidance from our Priests.
The writings of the Father are filled with references from both the Old and New Testaments. If you wished to know
X's interpretation of such and such a verse from Proverbs, for example, you would not necessarily find it neatly laid out in a book called
Commentary on the Book of Proverbs, but might have to wade through sermons and letters with completely unrelated titles. I don't think most of the Fathers are anywhere near as difficult to read as many people make them out to be, but that doesn't change the fact that the vast majority of people would neither know where to look nor have the time to do so.
Verse by verse commentaries quoting or paraphrasing works of the Fathers make the patristic commentaries accessible and systematic. As for asking guidance from priests, while this is by no means a bad thing, priests are not walking encyclopedias who will be able to give detailed answers about every verse of the Bible, and many are far too busy to give people individual Bible studies. Provided they are put together by competent and faithful people, I think such commentaries can be a very helpful tool for many (including the priests themselves).
