The game never really had a chance. Magic: the Gathering, while not a flawless game, has proven to be a very successful one. It was the first, it's one of the better ones, and it has such a great community, that the underlying problems never even come close to matching up to the greatness that its had achieved. I even joined in on the hype, but quickly found myself leaving it as various deck, culminating in Nekroz, made Yu-Gi-Oh! a more entertaining experience for me. Before that though, in 2012 and 2013, the World of Warcraft Trading Card Game left a deep mark on me. I had played the game before in 2007, using the "most broken" cards I could play, looking up deck lists, and playing many games using LackeyCCG. When I picked up the game again, early 2016, I reminisced about a great game. I will write a longer, more concrete, post about the actual game later, but for now, let's just focus on the simplest thing, was it good? Why did it get cancelled?
I take most of the early players entered the game from either another card game or World of Warcraft (the MMO), before declining until Cryptozoic took over. At that point, the game seemed to pick up steam as players began playing because they wanted to play WoW TCG, rather than just 'because'. The game was so close to exploding before it died, as StarCity Games had recently picked it up to tournament circuits. The big question is, how much longevity would it have had unless Blizzard had decided to pull the plug? In my firm belief, it was a mistake. I haven't looked into monetary statistics, so I may be wrong, put I think the SCG Circuit deal is a big thing. The game was slowly getting better towards its end, with the community growing fast on second-hand market sites and YouTube.
The game balancewise had a lot of ups and downs. Some of design was almost ingenious, like Ancestral Awakening, Calamity's Grasp, Illidan Stormrage and lots of the expensive but still good cards that would never have seen play unless WoW TCG incorporated it's excellent resource system. Having every card be a resource, along with Quest and Locations providing good value, lead to longer, grindier and ultimately more enjoyable games. It had its downsides too, such as allowing for hyper aggression, broken combos, or overpowered control decks. But in such a setting with moving system, some things are bound to break. Some cards felt like rip-offs from MtG, which was sad. One last thing I liked was the 'silly' cards, like The Horseman's Horrific Helm or Boomer. It's really the small things.