The Seahawks Ring of Honor faces a dilemma IMO, let me explain why....
No one has been added since 2005
All but 1 of the members was with the team in the 1980's (9 members from the 1984 team alone)
Frankly I think the Seahawks management figured out that the Ring was far too inclusive and because of this doesn't know how to handle the 90's era (Only Kennedy is in the Ring) much less the Holmgren years (Walt hasn't even been added yet) without creating a Ring that has too many names to display in the stadium and that is before we even get to the Carroll era.
Lets look at the accomplishments (as Seahawks) of the current players
Dave Brown-11 seasons, 1 Pro Bowl, 2 All Pro
Kenny Easley-7 seasons, 5 Pro Bowl, 4 All Pro, 1 Player of year, All Decade team
Jacob Green-13 seasons, 2 Pro Bowl, 1 All Pro
Cortez Kennedy-11 seasons, 8 Pro Bowl, 5 All Pro, 1 Player of year, All Decade team, HOF
Dave Krieg-12 seasons, 3 Pro Bowl
Steve Largent-14 seasons, 7 Pro Bowls, 1 All Pro (this shocks me), 1980's All Decade team, HOF
Curt Warner-7 seasons, 3 Pro Bowl, 1 All Pro
Jim Zorn-9 seasons
Now, I don't want to hate on any of these players because I have fond memories of all of them (save Zorn who was before my time) but what standard is being used for entrance into the Seahawks Ring?
Right now the rules seem to be 'Be an a solid member of the team in the 1980's' (Tez exception)
Honestly, if you think through the standards that got these guys there (really just a Pro Bowl season or 2), if we fairly apply the standards that got players like Jacob Green, Dave Brown, Curt Warner, and Dave Krieg into the Ring they will need to build a larger stadium. If you don't honor other Hawks with similar careers what is the point of the Ring?
I don't really have an answer here, just find the Hawks ring to be a bit of an oddity. My guess is that one of the main reasons no one has been added since 2005 is that the organization now realizes that the standards it was using cannot be maintained and doesn't have a plan at this point so the Ring remains at 10 members.