Early in a nascent industry, you focus on the core product. You bring scale and scope economies. You make the supply chain more efficient. You improve the logistics. More abundant basic food stuffs for everyone, and more profits for agriculture shareholders. A true win-win.
Later on when the industry matures, the easy wins are all gone. Logistics and agriculture is fully optimized. The only scope for improvement is in marketing, adding sweeteners, and cutting out expensive ingredients. Now it's a lose-win, but from the shareholders perspective only, it's a win.
The problem is, you can't just ask companies to act nicely. While that would be a good start, even if they genuinely wanted to, competition largely forces their hand. The solution is careful and minimal regulation, to deter the pathological late-stage optimizations.