Well, sometimes you lack real surgeons or they're busy, but that's an exception.
It's easier to clone people because you usually don't have to babysit them or stand over them to actively fix them up. You start the cloning process, prepare the bodybag and items, you check the % every once in a while and you can help other people in the meantime. Once the actual cloning is done, you fix them up in cryo. You just make sure the patient makes it from one room to another. You turn on the auto-eject feature and check the guy from time to time. Once that's done, the rest goes smoothly - the patient can grab his items. If there's something wrong, you get a clean SE. I'm speaking from the point of view of a Geneticist - it's really no deal. I don't want to keep surgeons busy with (semi-)dead people.
The machines do most of the work for you. You're not tied to one person and there's little or no risk of fucking shit up if someone were to disturb you - for instance, you can't simply walk away in the middle of a surgery. Likewise, it'd be hard to have another surgeon finish up the surgery for you. With cloning steps are clear, straightforward and flexible. Anybody can step in to finish the cloning.
Is it convenient for me? Definitely. It's multitasking-friendly and that's one of the most important aspects in SS13 IMO. Multitasking.