I suspect the criteria and rejection texts mean that if you have to walk across crops, or field boundaries that don’t have public access, then a wayspot is not accessible.
This is not the same as all wayspots on farms being non-viable.
Removed in the UK or somewhere else?
In the UK, public footpaths are PROW and it would be surprising for a wayspot on a public footpath to be removed because it is crossing farmland. By accessible I mean literally accessible at 0m (c.f. the issue with little free libraries which are often not accessible).
Different places, different land use and access rules 
In the UK, a PROW can cross private land, e.g., a farm. You are on private land but have legally guaranteed right to be there.
I believe if the farm have cafe , the cafe itself might be eligible (at least in that business area, including the playground, assuming its for cafe visitor)
In the other hand, I believe playground inside normal farm are similar like SFPRP and considered ineligible
In my city, we have restaurant which is inside real rice field. Its quite common also to have plantation which enable its visitor to pick their own fruit(they are selling fruit)