It is normal these days to see some degree of Dealer churn. Especially if they also carry a Japenese Brand, or BMW. Ducati won't push back too hard if you're already established.
Part of it is competition. For example, if I were a dealer rep for Honda, and had some dealers that had Triumph bikes on the floor, I would negotiate favorable terms for dealers who dropped Triumph.
The other issue is that Triumph represents a lower percentage of the motorcycles sold in the US. A dealer has to work hard to sell what they are allotted every year; they don't sell themselves. Which may in turn result in floorplan interest charges and general dissatisfaction between both the dealer and distributor.
I started TriumphRat.Net in December 2001, when my local Triumph Dealer went out of business. So I feel your concern.
The bottom line is that Triumph is an evolving company, having to make several adjustments along the way; and not everyone handles change very well.
Hope this helps - Keep The Faith