Comp TFC died the week Fortress Forever and TF2 were released.
I agree, when TF2 /FF released, the official death of 8v8 occured...but in all fairness, the true competitive side of TFC was on the decline starting in 2003. TFC, as a competitive game, stuck around because people loved the competition. Most of us (TDA) and other oldschool players were burnt out on the game since had already been playing it for so long, however there was no true replacement for that style of play. The only redeeming factor is that the TFC community continually formed new teams, with new players. Players that got better, stuck together on the same teams and became contenders. This is what kept leagues alive for almost 9 years.
TF2 doesn't have that, and faces a similar problem with declining competitive interest, with the major problem being no new teams forming...or at least teams forming that could actually make an impact. You get people burnt out from invite consistently not reaching LAN..then joining open. IM teams dying mid way through and only half the rosters going elsewhere, and open rosters just disappearing. In TFC, pubbers truly looked up competitive teams and had aspirations to play in leagues...they made that happen. In TF2, the average pubber just wants to have fun with unlocks, hats, trade servers, and A/D maps. Valve doesn't care about competitive TF2 because 90% of the people that play the game don't care about competitive TF2. I mean, there's "competitive" pub servers all over the place with HLSTATS pages...people truly enjoy that being their "competitive" tf2. That's just the reality. TF2 is their cash cow "F2P" game. The game isn't really taken serious as a competitive shooter, as much as that hurts to hear it's true. It will never be a quake, cs, CoD etc in terms of popularity or money.
In order to draw a crowd, you need the publicity, the draw of big name players and intense/competitive matches. TF2 doesn't have that. With the exception of a the 4 or so invite players that stream, i bet the standard pub player would have no idea who is even in invite. To be perfectly honest, i didn't even bother watching more than 1 or 2 matches this LAN. It's not fun for me to watch whatever team b4nny's on dunk on everyone else with little to no effort. I respect that he has put that much time into being the best player in the game, and gather the best players in their respective classes.....but there is no excitement anymore when you constantly know the end result. From a spectator perspective, i wish their would be some roster shakeups. Hell even if a "super team" formed, i doubt they would be any real challenge because in all honesty 4G in their current incarnation is the true super team. It's impressive from one side, and depressing on another. Now compare CS:Go matches...for example Dreamhack. Every one of the higher seeded matches were insane. Constant back and forth in some...huge comebacks in others. Games like this bring excitement to watch. TF2 needs that desperately.