Because it's excellent rule of thumb. When you need to run more than one process in container, you are forced to write scripts/service handler. This introduces

Because it's excellent rule of thumb. When you need to run more than one process in container, you are forced to write scripts/service handler. This introduces complexity to system and troubleshooting is much more difficult when things go wrong. However, on practical level, it has to be done occasionally especially when containerizing third party applications that were not designed for containers.