There are huge lobbies supporting seasonal and temporary worker visas.

For one area you mention – farming – there is a specific H-2A seasonal worker visa, and industrial agriculture is a huge lobby.

Hotels, resorts, and other venues use the H-2B non-agricultural temporary worker visas. For example, Trump's properties (in)famously use them to staff up during busy seasons. These companies are also substantial lobbies in favor of guest worker visas.

But these are all temporary work visas, not visas allowing for permanent work and residence in the United States. So they would not cover permanent economic migrants who end up in the restaurant sector or in janitorial work.