I'm not worried about it. People and players are emotional. The passion is what makes them so good, and so dedicated. Ken was very attached to the team that drafted him, and gave him the opportunity to become a star in the NFL. He experienced the highest of the highs in the NFL, and despite the fact that JS runs a tight ship when it comes to contracts, K9 was disappointed to not have the contract matched so that he could stay in Seattle.
The passion in such an emotionally powerful game can lead to an unreasonable disappointment. It's not that Ken doesn't appreciate everything that Seattle and Seahawks fans did for him, it's just that his understandably strong feelings come to the forefront when he starts talking about his career here.
He's a good dude, with a great father, and while some Seahawks fans are understandably disappointed that Kenneth Walker didn't toe the line when talking about his former team, we need to realize that his emotions and dedication are as powerful as ours. Give him a little leeway and recognize the love he also has for our/his team.