Its a good/fair question Stephen and I've not got any answers either, but I might suggest it could be some combination of any or all of the following:

Despite the fact they saw what a combination of Darren Woodson, Thomas Everett, and James Washington could do, they must feel that the position itself is made more impactful by the surrounding talent at CB and DE. There's some validity to that line of thinking but the TE's are more prominent in today's game and therefore the position's value has increased IMO.

When they have spent a Rd-1 or Rd-2 pick on a safety (Roy Williams, Tony Dixon) they've never seen that player turn the tide in the Win-Loss column.

They've witnessed that they've gotten reasonably good contributions from "cheaper" avenues; Brock Marion (Rd-7), Everett and Washington (free-agency), Xavier Woods (Rd-6), Donovan Wilson (Rd-6).

They've also been burned by bad early picks at the position: Charlie Williams (Rd-3), Tony Dixon (Rd-2), Awusu-Ansah (Rd-4), JJ Wilcox (Rd-3).

Lastly, without doing any research, my guess is that other than special teams, Safety may very well be, on average, the lowest paid position in the league? If true, they may not want to put themselves in a bind?

A draft like the one coming, where they have 10 picks seems like a good opportunity to re-try your luck with an early pick at Safety.