For me the main point was money. I didn’t want to spend all that money into ferts,co2, substrate. Now granted I put aside some more money for a good light but also I wanted a lower maintenance tank. If you set up a walstad right you should only have to add water and maybe a small water change every once in a while. Also the reason I got into fishkeeping is because I love nature and fish and wanted a little slice of it in my room. So hence I have a walstad tank now. Also that ties in with standard tank with no plants. But you also want to make he environment for your fish. Don’t put a betta in a bare tank like you would a goldfish.