Again Macrumors has a great article on the origins of iMovie 08, which became Final Cut Pro X.
Ubillos returned from vacation and found that Final Cut wasn’t ideal for organizing raw footage. From that experience, First Cut was born which would let you import your raw footage and quickly skip through, organizing and building a rough edit. The intention originally was to then export to Final Cut Pro. At some point, Apple officially latched onto the project and turned it into the new iMovie ’08.
No wonder so many features seem shoehorned, it was meant to just create quick rough cuts, not to be the whole editor!