No idea what gives you that impression. Why would I be defending a random person I simply read a Wikipedia article about? Of course I heard him broadcast football games. Hundreds of times, from the mid-80's on. I have a pile of videotapes of games he did with Pat Summerall (who was also amazing in the booth). I was lucky enough to have a personal conversation with him once.
He increased my knowledge and understanding of football immensely, and I'm certainly not alone. His contemporary broadcasters, like Cosell & Meredith, had no idea how to break down a nickel defense or the ability to point out the key block that opened a hole for Walter Payton or gave Troy Aikman an extra second in the pocket to find a receiver deep. John Madden did that consistently for two decades, with a passion and exuberance that was unmatched. He was able to clearly explain why Lawrence Taylor and Reggie White were so effective at causing chaos defensively -- but also, in the rare cases when they were neutralized, how o-lineman did so and what blocking schemes were frustrating them. He brought attention to players, especially lineman, who were generally ignored, and explained the concepts of blitzing and stunting and pulling and various defensive fronts to the masses, both why they worked and also how opposing coaches strategized around them.
If you weren't able to absorb any of his concepts and wisdom, if it wasn't "important" to you, well, that's your problem, but publicly posting so doesn't take away from Madden's greatness.
He increased my knowledge and understanding of football immensely, and I'm certainly not alone. His contemporary broadcasters, like Cosell & Meredith, had no idea how to break down a nickel defense or the ability to point out the key block that opened a hole for Walter Payton or gave Troy Aikman an extra second in the pocket to find a receiver deep. John Madden did that consistently for two decades, with a passion and exuberance that was unmatched. He was able to clearly explain why Lawrence Taylor and Reggie White were so effective at causing chaos defensively -- but also, in the rare cases when they were neutralized, how o-lineman did so and what blocking schemes were frustrating them. He brought attention to players, especially lineman, who were generally ignored, and explained the concepts of blitzing and stunting and pulling and various defensive fronts to the masses, both why they worked and also how opposing coaches strategized around them.
If you weren't able to absorb any of his concepts and wisdom, if it wasn't "important" to you, well, that's your problem, but publicly posting so doesn't take away from Madden's greatness.