I believe in some states a lease cannot be terminated without written notice before a certain date.  Sometimes the renter can force another year of renting that way because the landlord may not have been aware of the law.  In any case, the renter's days on the land involved are numbered if the landlord decides to make a change.

I think some renters are a little more aggressive in how they go about seeking more land to rent than they were years ago.  Farms have gotten to be spread out over larger areas, so it simply is not possible for the operator to build relationships with prospective landlords over time like they could when all of the land involved was within a few miles of home. 

A lot of the prospective landlords are not accustomed to and can be caught a little off gard by a high pressure approach from a new renter.  The prospective renter might feel like it's just a friendly business proposition, but the land owner could percieve it to be high pressure sales pitch.  Sometimes older land owners are not as strong as they age and could become succeptable to caving in when abruptly faced with something like that.  They might also be afraid to tell the current renter about the news.  Others might be offended and quickly show the prospective renter the door.  I do not know this based on my own experience.  It's just some of what I've seen, knowing people involved on both sides of land deals.  

Loyality still exists, but not with everyone.  It probably never did.  Loyality can be something one really takes to heart or it can be paper thin.  One cannot see the difference until it is challenged.  The idea is the same as always, but the forces that work against it change over time.

I have no way of knowing what happened in your friend's situation.  If one desires to control the land, it's best to own it and hope the government keeps their hands off.  Knocking on doors to get more land rented really is not my thing.  I'm not much of a salesman, so any piece of land I could get rented could probably be easily rented out from under me by the next person to come along.  Some have knocked on my door to sell me their land.  I am grateful for those opportunities.