Firstly, non-enforcement of trademarks results in losing said trademarks. I've been downvoted more than once around here for saying that, so here's a citation[1]:
> Trademark rights may also be lost when a trademark owner fails effectively to police its mark against eroded distinctiveness, which may occur as a result of the presence of confusingly similar third-party marks in the market.
Secondly, why pay for Starcraft when I can just play Starcraft-JS for free? Although I'm completely on-board with Startcraft-JS, I strongly doubt that Blizzard will react well to it.
> Trademark rights may also be lost when a trademark owner fails effectively to police its mark against eroded distinctiveness, which may occur as a result of the presence of confusingly similar third-party marks in the market.
Secondly, why pay for Starcraft when I can just play Starcraft-JS for free? Although I'm completely on-board with Startcraft-JS, I strongly doubt that Blizzard will react well to it.
[1]: http://www.inta.org/TrademarkBasics/FactSheets/Pages/LossofT...