Everyone hit on it.
Look, I loved MHS. I was in the soutstands for some big games there. It WAS louder. It was simpler and there was an old-school element to it that gave it some charm.
It was also a rickety old piece of crap. The thing was constructed on a landfil in the forties and added piecemeal into the eighties. Elements of it looked like somewhere a rapist would hide his victim. The whole concourse would sway when you came into and left the structure. There were areas that were going to become dangerous about it over time.
We needed a new stadium. The old one was gone. Yes, it had charm. Yes, it had nice memories. But it was structurally a piece of crap comparative to others of its time. Denver grew up and the Broncos grew out of Mile High. People piss and moan about the new Stadium and how the crowd changed. I think the crowd got disillusioned with years of patched together wild card teams and first round blowouts followed by the misery of the McDaniels years.
I was in the '98 Dolphins playoff game and I was in the 2005 playoff win against the Pats. Let me say I felt like the fans were just as into it in '05 as they were in '98. Is the Stadium a vibrating piece of Mad Max beyond Thunderdome that probably should be condemned? No. But Denver has good fans and waxing nostalgic about how a structure "ruined" Denver fans is stupid.