Season 1 is available on DVD/Blu-Ray and you can rent it from Netflix, etc. or buy/stream it from Amazon Instant Video. Season 2 is still only on cable or in HBOGo which makes sense as the season hasn't finished airing yet. That's like getting upset because the only way to watch The Avengers is in theaters. Remember, HBO is a premium channel; viewers pay extra to get access to new movies, quality shows, etc.
It would be cool if HBOGo could be accessed without a cable subscription. But no matter what HBO charged for HBOGo, people would still complain about the price.