Remember that bacteria colonize on the surface of filter mediums or on gravel. An aquarium with a heavy planting of tall background plants gives fish a sense of security. Fish need a place to hide or escape. An aquarium with no background is not suitable. Lack of security can lead to stress.
Some people prefer to have clean rocks and plants.
In this case the algae must be removed periodically. Basically, it's a matter of preference. Brown algae is a problem indicator. Its presence suggests improper lighting. For algae to be green, intense light is required.