"Knowledge" is a relative term. Unless someone played the game at a high level, worked for an NFL team or scouted, then they offer their opinions and back up the opinion. I can't differenciate "knowledge" per se, as we all put our personal spin on what we see.
In any event, Broaddus has been a scout and worked at the professional level but that doesn't keep you and some others from attacking his opinion and "knowledge." Same with retired athletes who work for NFLN, ESPN, etc. that offer opinions that happen to differ from yours. I don't see you and a few others defer to their "knowlege," experience and expertise. So sorry if I take your 1% comment with an absolute grain of salt.
Exposure to information does not make someone an expert. Broaddus has admitted that Helman has to write his stories because Broaddus writing skill is not past a 3rd grade level. If a guy is just not intelligent, all of the exposure in the world is not going to make him an expert.
Many ex-players are much like Morris Claiborne who scored about 6 on the Wonderlic. They learned their position with a lot of repetition but that does not mean that are great at using logic to analyze teams as a media member.
There are a few ex-football guys that really do have good knowledge, but those usually get sucked into the void of ESPN and become part of the nonsense that many ESPN employees have admitted that they are encouraged to become.
If you think about it logically, it stands to reason that some fans would be smarter than most "football people". Players and most coaches come from a pool of humans that were physically good enough to at least play college football. That automatically eliminates the vast majority of the population. Stephen Hawking was not going to become a football coach for obvious reasons but if tasked with analyzing football he could obviously make himself an expert.
A guy like Jermey Parnell didn't really know anything about football when he got to the Cowboys because he was a basketball player in college that played a few snaps as a DE in 6 football games. He just got a 32M contract because he has physical ability that the vast majority of humans don't have and even the vast majority of kids that played football all of their lives even through college don't have.
The Efe kid from Europe came closer than the majority to people ever do to being an NFL player despite the very most minimal knowledge of the game. He was here purely because of his physical ability.
If Parnell can develop into an NFL player worth a 32M contract purely on his physical ability then whey can't some people in the world develop a very high knowledge level of football purely on their mental ability?
It's a funny subject. I'll readily admit with no embarrassment that I don't have Byron Jones type athleticism. Heck I don't even have Jeff Heath type athleticism; however, almost nobody can admit that they don't have high level intelligence and indeed might be in the bottom half of the population from an intelligence perspective. You or most people would probably admit that you can't compete with Byron Jones but you would probably argue that your opinion is better than the opinion of a guy that works for NASA even if your career is cleaning toilets.
I expect to see more and more non-football people start to become GMs and scouts now in the age of advanced metrics and "Money Ball" type of decision making. The Texas Rangers have had the most success in their history with a GM that didn't play baseball. The Cowboys and other teams already have consultants that analyze stats for them. It would not be surprising if some of those consultants were fans that posted on message boards.
Speaking of the concept that you don't know who the people are that post on fan message boards, it's always possible that some posters have football backgrounds or have access to people that are employed in football. When you consider just all of the relatives of NFL players and NFL and college coaches, it is a very large pool and some of them are inevitably going to end up on fan message boards. My point being that a blanket statement that some "fans" can't have a very high level of knowledge or access to that knowledge when debating a subject is silly. That statement is just a lazy retort by people that can't argue the point on their own merit.