Cannot use SqlMapperExentions.Table attribute on structs

[SRNissen]

As it says in the title

    /// <summary>
    /// Defines the name of a table to use in Dapper.Contrib commands.
    /// </summary>
    [AttributeUsage(AttributeTargets.Class)] <------ right here
    public class TableAttribute : Attribute
    {

Is there any technical reason for this limitation or is that just how it got implemented?