Advanced Task Manager doesn't auto-kill anything unless you specifically tell it to. You can tell it to either kill everything that isn't on a list of things to not kill (i.e. an exclude list), or you can tell it to kill everything that is on a list of things to kill (i.e. a kill list).
If you just use the kill list and keep it set to just the apps you KNOW are OK to kill, then it should be fine.
The problem is that people don't really understand how Android works, so they kill off everything including a bunch of background services. Then complain when their phone locks up or they stop getting SMS messages or it lags when they get a call.
