Speaking as a beefarmer, we realise the little guys need a place to keep their bees. We have no issues at all about amateurs having a few hives on the same patch...just not right next door.
When we start to work with a landowner or farmer we like to ensure exclusivity, on the commercial level that is, so make it clear that the small guys with up to around 10 hives are no issue for us and we have no objections to them being around unless there ends up being a lot of them. We take their presence into account when deciding how many go there, otherwise we end up cutting our own throats on forage.
What we don't like are folk who masquerade as a small guy looking for a place because they are desperate...the landowner sympathises...and the next thing there are 40 hives almost across the fence. Often followed by an allegation that their bees died because the 'beefarmer' nearby had 'diseased bees' that made their own die........... trust me...it happens.
Its usually the small that fear the big and invent all sorts of reasons why they should have the place to themselves. As another poster mentioned, it IS the landowners choice who they have on their land, and it can be unreasonable behaviour by a small beekeeper that costs them their place, not the actions of the big boys, who generally not fazed by things.
The classic two in recent years, both encountered more than once.
1. The farmer has 500 acres of OSR coming into flower. He wants to ensure adequate supplementary pollination. He asks local beefarmer to place hives. Joe Bloggs with 6 hives objects and gets very stroppy with farmer. Joe Bloggs told to sling his hook. Beefarmer held to blame...and every malaise that then befalls Bloggs's hives is the BF's fault...even if they were never on the same patch at the same time.
2. You cannot allow these bees here. 'It is well known that the local bees around here are a special type not found anywhere else in the world (select from a long list of characterisitics highlighted) and incoming bees will destroy the gene pool that is a unique resource we might need when (not if!) all the other (inferior?) bees die off. (Truth...in at least two cases other beefarmers had been moving into the area every spring for many years, and several local beekeepers bought in stock too....and we are virtually local to them anyway.) Have had two cases of farmers being threatened with violence by other beekeepers. One told the small guy where to go, the other moved us on as he feared the outcome.