I disagree with almost all of your comments about SC2. All of the things you mentioned (no lan, no clans, allowing blord/infestor to go on too long, etc.) are just red herrings for the greater factors at play that kept SC2 from exploding. It was instead that the landscape of both SC2 and gaming as a whole changed.

As far as your complaints about westerners not winning anymore, that's proof that the game is good, not bad. Westerners lost in BW as well. All it shows is that the winner of the game accurately reflects which player is more skilled. Korea has a decade and a half of infrastructure and training behind their SC2 players. This makes their players more skilled and makes them win. The period where westerners were winning consistently was just a blip on the history of SC before 1) KESPA players switched to SC2 and raised the bar for KESPA players, ESF players, and westerners alike and westerners couldn't keep up 2) before the game was figured out. It would attract more viewers if other nations could compete with Korea, but for that to occur either the game would have to be unfair or westerners would have to actually be as good as Koreans.

Finally, gaming as a whole changed. SC2 came out four years ago, before the rise of MOBAs. Honestly, MOBAs are just better suited to mass audiences as far as esports is concerned. SC2 is an brutal, unforgiving, extremely difficult 1v1 game. MOBAs are free-to-play team games. In SC2 you are a commander of units. In MOBAs you play a single actual character with a personality and style you can identify with. Life's lings have personality, yes. As do MarineKing's marines. But Insec's Lee Sin? Madlife's Thresh? Those are actual characters people can latch onto. League/dota also generate many more highlightable moments, whereas SC2 is more of a tug-of-war.

SC2 is falling into its rightful place among esports... as tennis. A difficult 1v1 game. MOBAs are football. I'll keep watching SC2 because I love it and it's a beautiful game. It's a better game than it ever has been, and the amazingness of recent tournaments is a testament to that. I just don't expect it to explode any time soon.

Also, while not achieving the cultural status it did during wings of liberty, SC2 is at least maintaining its audience if not slowly growing. That's more than most games 4+ years in. I don't blame the slowing of this growth on the game, or on blizzard. It's just that the times have changed.