Geometry Shader not generating geometry for some Vertices

I am playing with a geometry shader and I am wondering why it doesn't generate geometry for each vertex in all meshes?

• I don't think this is a Cull problem because the same vertices generate geometry as you rotate around and setting Cull Off changes nothing.
• Another problem could be a multiply by zero somewhere but I tried to eliminate as many variables as possible and still have the issue.
• A third unlikely issue could be limiting the output amount somewhere. I didn't set anything explicitly to hinder that.

I notice the problem on a Cube(5/8) and Quad(2/4) but seems to generate all the geometry fine on a plane, cylinder, etc. The following are some results from using the bare-bones geometry shader.

Cube (closest: Unity default, further back: Cinema 4D exported .fbx cube):

Quad:

It seems to work fine on a plane (update: It is actually missing a whole row on each axis)

Unity Shader Code GeometryShaderTest1.shader:

Note: If you are testing out the shader and nothing is displaying; Rotate your camera around so the normals are facing the right direction to show up.

Shader "Custom/GeometryShaderTest1" {
    Properties {
        _Color ("Color", Color) = (1,1,1,1)
        _Amount ("Height Adjustment", Float) = 0.0
    }
    SubShader {
        Pass {
            Tags { "RenderType"="Opaque" }
            LOD 200

            CGPROGRAM
            #pragma target 5.0
            //#pragma addshadow
            #pragma vertex vert
            #pragma geometry GS_Main
            #pragma fragment frag
            #include "UnityCG.cginc"

            // Vert to geo
            struct v2g
            {
                float4 pos: POSITION;
            };

            // geo to frag
            struct g2f
            {
                float4 pos: POSITION;
            };


            // Vars
            fixed4 _Color;
            float _Amount;


            // Vertex modifier function
            v2g vert(appdata_base v) {

                v2g output = (v2g)0;
                output.pos = mul(_Object2World, v.vertex);
                // Just testing whether all vertices affected
                output.pos.y -= _Amount;

                return output;
            }

            // GS_Main(point v2g p[1], inout TriangleStream<g2f> triStream)
            // GS_Main(line v2g p[2], inout TriangleStream<g2f> triStream)
            // GS_Main(triangle v2g p[3], inout TriangleStream<g2f> triStream)
            [maxvertexcount(4)]
            void GS_Main(point v2g p[1], inout TriangleStream<g2f> triStream)
            {
                float4 v[4];

                float3 asdfUp = float3(0, 1, 0);
                float3 asdfRight = float3(0, 0, 1);
                v[0] = float4(p[0].pos + 0.25 * asdfRight - 0.25 * asdfUp, 1.0f);
                v[1] = float4(p[0].pos + 0.25 * asdfRight + 0.25 * asdfUp, 1.0f);
                v[2] = float4(p[0].pos - 0.25 * asdfRight - 0.25 * asdfUp, 1.0f);
                v[3] = float4(p[0].pos - 0.25 * asdfRight + 0.25 * asdfUp, 1.0f);

                float4x4 vp = mul(UNITY_MATRIX_MVP, _World2Object);
                g2f pIn;
                pIn.pos = mul(vp, v[0]);
                triStream.Append(pIn);

                pIn.pos = mul(vp, v[1]);
                triStream.Append(pIn);

                pIn.pos = mul(vp, v[2]);
                triStream.Append(pIn);

                pIn.pos = mul(vp, v[3]);
                triStream.Append(pIn);
            }

            fixed4 frag(g2f input) : COLOR {
                return float4(1.0, 0.0, 0.0, 1.0); 
            }

            ENDCG
        }


    }

    FallBack "Diffuse"
}

Geometry shader resources:

• Geometry shader with shadows not displaying shadows properly - Unity forums
• This isn't exactly OpenGL but good info: Geometry Shader and Vertex Shader
• Billboarding Geometry shader example here and here