I think it's a "damned if you do, damned if you don't" thing. If you make the law sweeping, businesses will complain it's an infringement of big government. If you make the law targeted, businesses will complain they're being unfairly selective.

What other industries do you think would benefit from this? Warehouse work might be unique enough to be afforded unique protections. There a lot of dark patterns you can employ against your workers in those settings, creating orders that are hard to fulfill on time, arranging your warehouse in ways that reduce worker productivity or even safety. Since many warehouses are moving consumer items and often food items there does seem to be reason to consider them separately from other industries.

They also have a separate labor union in many regions.

Linking my answer to another comment asking the same question: https://news.ycombinator.com/reply?id=40724535