You don't have to use the sweep button if you don't want to Crazywulf. No one is forcing you to do it. If you want to fight manually you can still do it. Battles take time and for some people who can't spend hours in the game, sweep is very useful to earn time and progress.
When there are days you can barely find 30 minutes, even less, to play yes...even an hour is too much. Like I said, "sweep" is an option which is good to have. If you don't want to use it, no one is forcing you to.
I agree, for those who say too much sweep will reduce the gameplay i remember you what you still have to do the campaing missions you dont have by hand, and HOL, and crucible, and raids, and, and, and... also gaining 3 stars on prophecy is not easy at all at highers level, so why not to sweep once you have probed yourself able to do?