Unconstrained generic type does not have the software scalability.
Only with a generic type constraint that has the software scalability.
Type with constraints in the system have the generic structure vitality. The reason it's part of the dynamic uncertainty, and contact with the generic mechanism of this part of the uncertainty.
Unconstrained type, can only be used in a generic pointer mechanism, and the like regardless of the type of reference characteristics contact with the generic mechanism; thus limits its scalability and flexibility.
In a sense, unconstrained type is the strongest constraint. That it can only be involved in the organization of generic mechanism in the form of pointers and references.
In a sense, it is extended for generic programming is to face the type of constraint programming.