i think they have a place however it should be based on your level,
Level 1 - 9 = shops have Gray and Green items, base item Lv 100-200,
Level 10 - 19 = shops have Green and Blue items, base item Lv 200-300, Lv 1-2 Blessings.
Level 20 - 29 = shops have Blue and Purple items, base item Lv 300-380, Lv 2-3 Blessings.
Level 30 = shops have only Purple items, base item Lv 360-380, only Lv 3 Blessings.
this way when at max level you would have good options for weapons in the Armory.
with all items being Purple and having Lv 3 blessings you would know most the weapon stats.
this would give you much better view of what a weapon is and what it can become.