It depends on whether his goal was to be on an NFL roster and making a nice salary, or playing a meaningful number of snaps in an NFL regular season and making a difference to a team. You are right. He has been on the Bills' roster for years, though some of those years he lost completely to injury, spending them on IR. It's also true that hundreds of players come and go in the NFL leaving with fewer years than Doyle. I still think he leaves wishing his career had been a little more.