It absolutely is, and it's my preferred version. But I think I remember seeing somewhere that the vast majority of unit sales were of versions that were written in C++. My guess is that, if it had stayed Java only, it would have still been extremely popular, especially by indie game standards, but would not have become quite such a global phenomenon.

The C++ versions may drive new sales on additional consoles but measured by hours played I would expect that the Java version of Minecraft still dominates.