I had Korean, Chinese Pinyin and iWnn IME Japanese on my tablet as well, all disabled but not removable.
Have a theory it's there for the sake of compatibility. I remember from browsing on PCs I would see weird box shapes on certain websites when in fact it was because I was missing chinese/japanese language packs.
| OnePlus One 64GB | ROM: CM Nightly |
| Recovery: TWRP | Kernel: Stock |
| Nexus 7 16GB (Wi-Fi) | ROM: 4.4.4 Stock (rooted) | Xposed |
| Recovery: TWRP | Kernel: Franco |