Crossbreeding of Boa c. subspecies (hybridization is the crossing of two species in my understanding) had happen so often in the past that there is a general uncertainty in boa owners.
Those who give a damn if their animals are pure or not are not affected by this. But there is a significant number of people who want to be sure that they buy a true boa c. These people need a load of luck to get animals where they can be sure to buy no crossbreeds (except they buy wildcaught animals, and this is not what we want).
The crossbreeders freedom to do what they want curtails the freedom of buying pure animals.
There is a word for such a behaviour: inconsiderate