Hi Hdharris,
Thanks for comment.
Sure, I also can't recall the last time I used a fishing rod... oh... wait I don't go fishing. (This is a joke that means: It all depends on the thing you like to do.)
Now, getting serious, I understand that many users don't use the "Quad View" or need one... it all depends on how "one's" brain "works" when modeling /sculpting?
For me, I'm an old school modeler kind of person, more than anything else.
My main tool was "Lightwave Modeler" for many years so the "Quad View" is like "hardwired" in my modeling /texturing process (and there's nothing wrong with it).
I started using 3Dcoat since the beginning, mainly for Texture Paint.
When I mean beginning, I really mean when Andrew first visited the NewTek forum to collect ideas on how to create "3D Coat".
Later he gave us the Alpha and Beta releases to test... fantastic times, so long ago.
I'm now adopting Blender (since LW development has stopped) and I use "3DCoat 4.x" mainly to apply PBR materials on my models.
Fortunately Blender also offers a Quad View mode UI.
About your question: "why is that the line for being an official 3d software?"
I'm sure you noticed the "huge smile" ending my sentence... so yes... I made a "kind-of" a joke but joke or not the sentence carries some truth in it since all well know 3D CG programs offer the Quad view IU option.
So, please, let it be.
Cheers, stay safe.