Let's start with the definition of "exclusive." I'm guessing that it means only one integrator in a given market has access to a product. It can also mean access to a discount level that is "exclusive" to an integrator that helped move a manufacturer's product into a specification or end user.
Exclusives on products are counter-productive in many ways. First, there may be anti-trust issues under anti-monopoly laws. Also, end users should avoid products that are only available through one distribution point. The security industry typically doesn't see this but, it exists in the fire and controls industries.
That noted, "open" product distribution puts end users at the mercy of a very large electrical pool with little to no quality control. If a manufacturer has more than 4 existing integrators in a geographic territory, it's very unlikely that I'll invest in training technicians, sales people, and stocking products.
As far as an exclusive to a discounting level, imho, manufacturers and/or distributors should be able to offer unique discounts IF there is value in exchange for that exclusive discount over the rest of the market. Otherwise, it's likely unfair trade restraint.
Best,
David Coughlin