#once upon a time...
there was a developer, he had to realize a nice clean greenfield project with any framework he like.
He had no idea which PHP Frameworks were outside there and after a small research he decide to use Kohana 3.2 because at this time this was the only one framework which the developer could understand and use.
after 9 months of developing the project was born and launched. the developer realized that a new version of the Kohana framework was released, it was a minor release.
one small simple update to Kohana 3.3 and the entire project was broken, he reverted the framework update.