Still an intern should've been able to do 50+ companions with detailed backstories, dialogues, special events, secret quests in max a few years and that's working part-time. Lets not forget these people are supposed to be doing this for 7-8 hours every day.
This is really strange indeed. Considering the amount of time the game has been in development, aswell as the ease with which what you just wrote can be done, it is baffling that there isn't literally 50+ companions with handtailored backstories. Hell, I could probably write 50+ companions with detailed backstories in a couple of weeks, if I was working on it 7-8 hours a day.