Sorry, but Lynch signed a contract to make millions of dollars a year. Despite what we would like, that does come with more than just playing football. Part of his contract is to be available for the media for questions after the games (and I believe at least once during each week of practice). You have to fulfill the contracts you willingly enter into. That is part of being a grown-up.
It really isn't up to me to decide rather or not Marshawn Lynch is acting inappropriately with reporters. The NFL fined him for not talking to reporters and the NFL is the one that gets to decide what is and isn't appropriate. He has a contract and a job, it's between him and his employer.
In the age of Twitter and countless other forms of social media, the demands made of professional athletes' time and energy are greater than ever. Being an athlete in and of itself is exhausting enough, and when you add on top of that the constant nag of reporters digging for a headline, it's perfectly understandable why Marshawn Lynch would act the way he has acted lately.
While Marshawn Lynch is obliged to speak to the media, his contract doesn't stipulate exactly what he has to say. Therefore, while his behaviour may seem churlish he is obliged to say whatever he likes to the media. He is not being impolite in his contact with the media and so could not be accused of being unnecessarily inflammatory.
While it is understandable to say that those in the public eye need to engage with the media, Marshawn Lynch has clearly stated that he is uncomfortable with reporters. Many reporters clearly attempt to try to get Lynch to react to get an even bigger story. There are many players and coaches to talk to, and the media should focus on them for their stories.