Might be more accurate to say that it was at a standstill for years.
Yes, they release bug fixes and minor features often now... but the game is almost identical to what it was years ago.
The only really big thing I know they've done lately is make the game properly multi-threaded, and while that is a big and worthy accomplishment, that should have come years ago.
Reading /r/minecraftsuggestions shows that most people ideas of vast improvement are sub-optimal.