The Redskins were quick to sign the 27-year-old as a free agent, and Williams believes that the three-time Pro Bowler has already proven his critics wrong on the field.
"Picking people apart is a byproduct of that attention. For a guy that has had the type of impact he has had, I wouldn't question his practice habits or question him as a player. He's proven himself day in and day out," Williams told reporters.
"It's human nature, whatever you're doing and all eyes are on you, there's somebody that won't like you. There are always people that say things, so I'm not going to judge him and say he needs to change.
"I can only go on his body of work and his numbers can stand up with the top receivers in the league."
Williams also revealed that he had got to know Jackson at the Pro Bowl and insisted that he had no problems with his character.