To say that Kearse is a good, bad, or average WR misses the point. He is a very skilled red line receiver that is flawed in other areas. Our team is largely made up of players who are exceptionally good in one specific area but very weak in other areas. JR Sweezy dominates on the move, but gets his ass kicked by power rushers. KJ Wright can blow up a screen, set the edge, and make a good open field tackle, but he has poor trailing speed and takes poor angles. Kam is a bawse when going downhill, but you wouldn't want him covering Gronk. Even our QB has big strengths and big weaknesses.
The fact is, our WR group leaves a lot to be desired on red line targets deep down the field. Last year Kearse was the only WR that Wilson would trust deep when covered. And for good reason, Kearse high points well and has strong hands. He makes the tough catches on the deep ball better than most WRs in the league.
The red line deep ball is a crucial component of the Hawks offense, and right now the other WRs are not earning Wilson's trust on the deep ball the way that Kearse is. Kearse is not a great WR, but if we cut him tomorrow, our deep passing attack would instantly be much worse.
Kearse does have some issues turning targets into receptions (much like Kelvin Benjamin), though his actual drop rate is lower than most would think. I think he is a below average WR who is way above average on the deep stuff. Once our team has 3 other WRs that Wilson will trust deep when they are covered, Kearse will become easily expendable. But right now, Baldwin only gets targeted deep when he's WIDE open, and though I think Lockett will probably be awesome on deep targets, we haven't seen it yet. Same thing with Matthews, other than 1 deep catch in the SB.
Kearse was a free agent and Seattle put a relatively pricey RFA tag on him. Not out of loyalty, but because he offers a much needed skill that our current WR group is in short supply of. Seattle could have easily just said goodbye to Kearse this offseason, but instead they paid a decent chunk of money to ensure themselves that he was a Hawk in 2015. Why would they do that for a player who's mediocre on the whole? Because Seattle is all about specialists, and Kearse provides a skill on the red line that the team needs pretty badly.
That doesn't mean I want Kearse to be a Seahawk for life. I am fine with moving on from him right now, if I felt the rest of our WR corps could make his deep route skill expendable. But as I see it, the other WRs are still a long way from making that a reality.