Teams who place a low value at certain positions will continue to have a "problem" at those positions (whether they realize that position is the "problem" or not)....until they learn that all of them matter.
I recall many years with this team (seemingly through 2 coaching staffs) having "tweeners" at both safety positions. That used to drive me crazy and, having said that, one might think that Bernard Pollard is just what we needed at SS. I don't know how I feel about BP, but I know that I have always felt that this team REALLY, SERIOUSLY needs to get a good, ball-hawking FS. I don't know if it's Quinn, Nolan, a free agent that we need to pay for, or a high draft pick to groom, but I feel like that is a crucial piece of the puzzle....especially when compared to our draft history, which I will slightly exaggerate by quoting "DT, DE, DT, DT, SS, DT, OLB, DT, DE, DT, DT, DT, DT, DT..."
If it don't work at all after years of trying, TRY SOMETHING ELSE. Heck, this is joking, but we created a great offense while drafting 80% front 7 defense, LOL. I just don't think we are going to fix the secondary by drafting DTs. I just really don't.