RE: Why inheritance is not supported by structures??
What used to be a struct in original C language moved on to C++ and then C#. Although lot of class capabilities have been added into struct its purpose is to just group together few fields and may optionally contain some methods for their manipulation. The inheritance is a powerful object oriented concept implemented through classes. Structures (struct) are not appropriate for replacement of classes while classes could easily be used in place of structure. In fact you can do virtually do any thing with classes -- structs are still around primarily for historic reasons.
RE: Why inheritance is not supported by structures??
Structure support only interface inheritance but it don't implementation(class) inheritance. Most probably bcoz its language(C#) feature and avoided due to complexities arised implementing it.
RE: Why inheritance is not supported by structures??
The Main facts for Inheritence to any thing that is it should worked as Base. And Structure could not worked as Base due to it is Value type. So Inheritence is not supported by Structure.