Theres too many variables in all of this to blame a certain reason for the decline in activity or skill. Its just a combination of all of these factors that has resulted in the reason why wormnet is like how it is now.
If we try to analysis all these factors then maybe there is an outcome that can be taken so maybe based on the arguments above i'll try and summarize what has been said so we can look at next steps to take.
Hysteria
People are blaming hysteria but i don't see this as the problem. schemes are born and schemes die, some schemes in the history of worms used to be in the leagues and aren't now because they gradually lost interest of the players. Fort and Pro for example, etc.
Games evolue and although there may be no depth to hysteria it is still a competitive game that some players are better at than others and i think its justified to be a league scheme as much as i personally dislike the scheme, taking away something that new players enjoy isn't the right answer, they are the majoirity and the hysteria era player (the people who learnt it as a first scheme) go on to learn t17, elite and other schemes because they play classic scheme. Your overall skill we prevail and theres a reason why Random00, Mablak and Almog are tough to beat in hysteria, because they are consistent top league players.
Tus features
Again, these cups and different leagues like HAL and whatever do draw attention away from classic league. But they are popular and it is what the new players of today want to play? I guess there has been a drop in classic league activity for long enough that these players are just interested in these other type of leagues.
Look at TUS league as a company and wormers are its customers, a company is going to have a range of products to offer to its customers and companies review their products from time to time and examine what is working and what isn't working. If there is demand for these leagues and cups then TUS is going to support them because its giving those players something fun to do. You can't blame TUS for supporting these sub leagues because its the market of wormers that wanted them as they have created demand for it.
So where is classic and clan league in all of this? its in decline and when a product is in decline is usually dies or something is done to add an additional feature etc to improve it. So MI and others have tried to improve features to do this but maybe it hasn't worked. But that isn't TUS's fault, its ours. We are the players that are interested in the classic league yet collectively we arn't as active due to many reasons that lalo has pointed out.
Perhaps there could be less focus on the cups and sub leagues and less trophies and awards. This just comes down to design and display and these features in the league. IF classic is the most important accolade in worms than represent this in a visual design aspect of the website.
How much time does MI have to create a new design, probably not much. You shoudn't remove features, but the design could be changed i guess... But in general its our fault for not playing as much and less role models for new players to look up to and play against. So its easy to play in a cup or whatever because you arn't learning all the schemes to try and beat the best allround players. But to remove the free league schemes to encourage classic league isn't the answer.
Or we could be exterme and do it to try and change that community and give them only 1 option of playing classic scheme.. It could go horriblely wrong and all those players just quit and wormnet is even worse.
life
We all grow up and have responsibilities, 9-5 jobs, university degrees, houses, kids etc. We've all grown up with this game and i doubt many of us older players can sit at home on an evening searching for clanners untill 4-5am like we once used to. Nothing can stop us getting older but the only thing that could make things better is the desire to play wa again. That desire isn't as strong because the league isn't as competitive but we all still have a passion for wa right?, we are a community because we all deep down love this game. This thread has about 6 players discussing a game we've all played for over 10 years and Anubis, ropa, fada. We've all grown up knowing eachother on wn, so if we love this game so much why arn't we in ag looking for games? Maybe we can't but wa won't die because people like us are still here debating and trolling threads lol
technology
Theres so many other new games, streaming, netflicks, you name it, loads of stuff to do in your spare time that isn't playing w:a. Because of this there is a massive decline in the amount of time us older players will spend on w:a but more importantly it stops new players coming into the game and learning schemes and getting into classic. Yet in ag now there are plenty of noobs, its just about getting them into league games.
So whats the answer? I don't know. not a single person can change it and solve this problem, it has to be collective, but if we are here concerned about the quality of classic leagues then that is a start because as i mentioned, the power is with us to log in and search for clanners again. If we can be bothered.
Quick fixes?
Reducing the number of games required to reach clanner POs would help.
Maybe a microsite for cups and free leagues can be placed on a second domain so the first thing you see on the homepage of tus is all Classic league related, then all the different sub games are placed on a secondary site, the design would them promote classic being the top accolade to a certain degree..