FAcy cost the team 2 in the secondary, a RB and Edge. Strengthening the OL seems like a good idea but you've got to choose. There are (were) literal holes in the roster. The 25 team won the SB. Do you try to strengthen a group that was elite enough to win the SB? ...or fill a hole that that is no longer on the SB winning roster?
I'm sure it's not as black/white as that, but understandable with the current picks.
The two 6th rnd picks could turn into more picks in the 7th. JS has used those for UDFA-type players that he didn't want to lose. That post-draft melee may be a huge focus for Seahawk FO this year considering the few picks and talent level in higher rounds. Seahawks normally do well with UDFA, but I could envision JS spending a lot of time and effort here pre-draft and that resulting in a large number of competitive players.