Automapper ForAllMaps is ignored

AutoMapperGlitch.cs

using AutoMapper;
using System;
using System.Collections.Generic;

namespace AutoMapperGlitch
{
    class Program
    {
        static void Main(string[] args)
        {
            var semester = new Semester
            {
                Id = 42,
                RowId = Guid.NewGuid(),
                Name = "SemesterName"
            };

            var dto = semester.ToDTO();

            Console.WriteLine($"{dto.Name} ({dto.Id})");
            Console.ReadLine();
        }
    }

    static class CurriculumMapper
    {
        private static IMapper Mapper { get; }

        static CurriculumMapper()
        {
            Mapper = new MapperConfiguration(cfg =>
            {
                cfg.CreateMap<Semester, SemesterDTO>();
                cfg.ForAllMaps(MapId);
            }).CreateMapper();
        }

        private static void MapId(TypeMap map, IMappingExpression mex)
        {
            if (!map.SourceType.IsSubclassOf(typeof(EntityBase)))
                return;
            if (!map.DestinationType.IsSubclassOf(typeof(DTOBase)))
                return;
            
            mex.ForMember("Id", opt => opt.MapFrom("RowId"));
        }

        public static SemesterDTO ToDTO(this Semester entity) => Mapper.Map<SemesterDTO>(entity);
    }

    #region Types
    class EntityBase
    {
        public int Id { get; set; }
        public Guid RowId { get; set; }
    }

    class Semester : EntityBase
    {
        
        public string Name { get; set; }
    }

    class DTOBase
    {
        public Guid Id { get; set; }
    }

    class SemesterDTO :DTOBase
    {
        public string Name { get; set; }
    }
    #endregion
}