If a mid-round talent at QB drops to the 7th round, then sure I guess draft him...But why in the world should we waste a 6th/7th-round asset on a 7th-round/UDFA talent at QB when we can 1)sign him as a UDFA, and 2)use that pick to draft a mid-round talent at another position who is falling into our laps? Same reason for NOT drafting a mid-round talent in the middle rounds...
We need players at multiple positions, and in some cases multiple players at the SAME positions...Using a 3rd/4th-round pick on a Fromm/Hurts/Morgan-type is terrible asset management...IMO...