The SC2 train stopped because it stopped being the darling of all esport fans. All the other developers have a monetary interest in improving their competitive aspect because it makes them money, even if indirectly. Blizzard does it because they like being the nice guys, but it IS just PR money. There's also the problem of sustainability, I mean GSL just had what people describe as the best finals ever. I woke up late just to see the award ceremony. If I want to see the games, time to subscribe and use twitch vods (!!!). That's not how you increase your viewership and apparently nobody cares enough to even pirate the vods.
The scene got really big really fast, people were surprised by all the retiring when SC2 and BW collided, but it's pretty obvious that the scene has just deflated to a sustainable state. There was also a lot of fatigue, at least for me. I alreadysawmost of the games, none of the victories really matter since there's a tournament in two weeks where they will play again... It's going to blow up a bit with LotV, but unless Blizzard figures out something better than just throwing money at it, it will never reach MOBA appeal and I don't think that's bad. In light of all these changes, I find it surprising that they actually scrapped the marketplace, but I guess they couldn't figure out how to make it work and given the state of custom games, I think it's for the better.
We might even see them cutting up the game into content chunks, like ranked/unranked costs 5$ per season, each campaign costs 10-20$ with a free ranked season ticket included and custom games or arcade is F2P. Give out some pretty skins and portraits for every season ala HS. If they cranked out a campaign per year without any cinematics, I'd be happy to throw money at them.