Biotics are cooler
The bare bone idea of the force is cool; choking a guy to death with your mind for not retrieving the rebel plans is an effective way of keeping guys in check. As is zapping Samuel L Jackson with a surge of finger lightning. Although the 'good guys' are pretty well endowed with force powers they spend most of their time lifting stuff up or throwing stuff away - which actually is a bit rubbish if you think about it.
Sadly, Star Wars made a booboo when it got weird on us by trying to explain the Force in Episode 1, midichlorians turned the once-cool superpowers into a yawn-inducing, eye-watering, childhood-shattering science lesson.
Mass Effect's biotics pick up the pieces. These blue doozies aren't as all encompassing as the invisible omnipotence of the force but they're brutally potent. There's nothing cooler than unleashing a molecular warp on a crap load of Cerberus troops, curving a mass effect field over some cover or throwing yourself towards an unsuspecting enemy in an all-powerful biotic charge.