Not exactly....
It loads and is not needed... wasted CPU/battery... and memory. It loads and that memory is needed by another program... more wasted CPU/battery.
Truth is... we are almost always talking about programs that your phone provider has load automatically. Yes, some programs load others but _most_ load because the phone provider wants them to load... not because it makes anything faster (I never bought anything from the Amazon MP3 store and never will... so it does not need to load).
Again, when programs like this load, it uses CPU/battery. When the system needs to recover this memory, it uses CPU/battery.
The other issue is that these programs _don't_ reload right when they are shut down. I can go most of the day, if not days before certain programs are loaded again.
You then also have many programs that continue to run even after they are exited. There can be no blanket statement that these programs don't use CPU/battery... each program is different. As others have mentioned, my phone has been slow... I shut some programs down in memory and it runs much faster. This is just a fact.
In a perfect world the OS would handle all of this and do it perfectly. Its a good thought and most of the time... it works. But not always. As such _TASK KILLERS ARE NOT POINTLESS_.... and you _cannot_ say that they use more battery then they save.