"Why" is a good question.
No Debian, Ubuntu, Mint version has Tesseact 3.
But it's easy to build Tesseract for Mint 11 :
sudo apt-get install zlib1g-dev libtiff4-dev libpng12-dev libjpeg62-dev
cd tesseract-3.0.0/ && ./configure && make && sudo make install
Will provide :
/usr/local/bin cntraining combine_tessdata mftraining tesseract unicharset_extractor wordlist2dawg
May be some more hints here
http://ubuntuforums.org/showthread.php?t=1647350
.