I guess they are a good idea if they work for you. However, human waste is not a benign substance. It should be processed either by aerobic or anaerobic digestion.
Aerobic, such as composting, stabilizes the material converting most of it to CO2, ash, and water. Otherwise, it can polute groundwater.
Anaerobic, such as closed vessel digestion (a step in the commonly used trickle filter system used by most municipalities) converts it to methane gas, ash, and water. This system is very efficient. The water released my a well-run system is often cleaner than any local water source treated later for human consumption.
If you want to lead a much more earth-friendly life-style and city codes permit it, go compost toilet. However, you will still be generating "gray water" from non-toilet processes. This will need to be bio-filtered (shallow water feature with plenty of aquatic plant life and sunlight) before it is safe to release into surface water.
I have more than 15 years experience in the composting industry. I familiarized myself with municipal waste management starting in the very early 1970's.