Striking in MMA

I'm hoping someone with more experience could help me. I read a lot of threads about fighters who don't have great standout or are afraid to strike or aren't boxing quality. Wouldn't it be due to the fact that they're also ready for TD attempts? I know when I spar, which my hands are slow, I'm very hesitant to stand and box because I know with one jab I can be on the ground defending advancing positions. Could someone elaborate for me, the striking aspect in MMA as opposed to boxing? Phone Post