He cares more about it than you do, hence why he is taking his time. Don't like it? Go write your own international successful book series then and see if you can beat him. If not stop complaining about it. We all want to read the new books asap, however he is the one doing all the work, so it's just pitiful to say things like whether he cares or not.
Also people Harry Potter and the Song of Ice & Fire are two very different series. The first book of the latter series is large enough to cover completely the first two or even three books of the HP series. On top of that HP was seen through the eyes of only one character and the largest part of series occurred within one building. SOIAF is seen through the eyes of countless of characters which are spread over several continents and GRRM has to make all of that work out correctly both chronologically as geographically. That's extremely difficult, even more so when you take into account he gives a lot of information about the history of the world he is writing and again all of that has to fit.
Lastly as I recall GRRM is working closely together with the makers of the TV series, so that shouldn't be a problem.