Aquaponics, the integrated production of fish and plants in a recirculating system, has been promoted as a sustainable agriculture solution capable of reducing water use by 90-95% while producing protein and produce simultaneously without synthetic fertilizers. Despite decades of enthusiasm, commercial aquaponics remains economically marginal, with most operations failing to achieve profitability. This article synthesizes recent life cycle assessment data and systems engineering principles to examine why aquaponics struggles to scale. Key constraints include high energy demands (particularly in northern climates), dependence on industrially produced fish feed that undermines "closed-loop" claims, nutrient imbalances requiring synthetic supplementation, and capital-intensive infrastructure that cannot compete with conventional agriculture on cost. Decoupled system designs, renewable energy integration, and strategic market positioning offer the most viable pathways forward, though aquaponics will likely remain a niche rather than transformative agricultural technology.