I do get why people like community tanks. They like different fish and like variety. Would you keep parakeets with canaries and finches all in the same cage ? Would you keep gerbils together with Guinea pigs and hamsters ? Not trying to stir up a hornets nest but I keep species only tanks and have for most of my aquarium days. The fish are more relaxed and show their natural behaviors. They seem more likely to spawn and they all get fed without competition.