Why? Because Universal believes in the multiverse theory, that’s why. They believe that, every time they make a movie, they create a universe where all of stuff in the film happens. This in itself might not seem so bad, except that Universal’s planning department is clearly under the control of a sadistic death cult that revels in pain and depravity*. By creating these movies of clever bloodthirsty dinosaurs and deeply, deeply stupid and self-destructive humans**, the cult can sacrifice entire worlds to their dark overlords, cackling in glee every Friday afternoon as they writhe in orgiastic frenzies…
Also, Universal just wants to personally annoy me by almost never doing feathered dinosaurs***.
*This is a joke.
**Seriously, the people in these movies have the survival instincts of pandas.
***This is also a joke. Not the part about me being annoyed; the part about Universal doing it deliberately.