The people who are taught how to use it are not the problem. The problem is that they need to be taught.

Personal anecdote:

The first 3D software I used was Cinema 4D. I couldn't be bothered to watch a tutorial, but in a good 10 minutes of clicking around, I could already do more than half of the most common operations. I tried using Blender several times before and after that, but after the same amount of time, I couldn't do literally anything. Not even move the cube! After switching to Linux, I finally forced myself to watch a few Blender tutorials. I can now do things better and more efficiently than I ever could in C4D. But the moment I switch to another tool (Unreal/Krita/Inkscape...), I see just how non-standard Blender is. There's always the Blender way and the everything-else way.

2.8 is a huge step in the right direction. Maybe one day multi-select will make sense and then there will be no more reasons not to use Blender.

Blender was my first modeling software, and learning on it made everything else frustrating for many reasons beyond controls by comparison. I also come from a Linux background, so modal softwares like vi were not a new concept.

So I wouldn't say that Blender's controls are inherently obtuse or more difficult than others, but that other popular software follows conventions that are more familiar to people with a subset of similar experiences.

What’s the issue with multi-select in Blender 2.8?

As a counter point: I've used a bunch of 3d modeling applications, starting with the Max Payne and Unreal level editors back in ~2002, and have since used SolidWorks, 3D studio max, modo, zbrush and various iterations of Blender throughout the years.

The controls in Blender are so terrible for me I've basically always given up in frustration within an hour or so.

The reason I didn't customize the controls is because I shuddered at how awful the UI for doing that probably was, and feared other lurking UI terrors were I to invest in adopting the app.

the thing is, all 3d software ever is an UI nightmare, almost inevitably. it's all very complex software that tries to do way too much at once, and even Cinema 4d with all its initial beginner friendliness that has made 3d accessible to a lot of people that were afraid of it before wears off once you try to make something non trivial (did you have to make a deformer a child of an object or the other way round? what operations do you need to make an object editable for? what about needing to change the order of objects in the manager for certain things to work? how to reconnect missing textures for a project? - those are all fairly basic things that i need to look up again and again, because they are not as obvious as they should). Maya is such a clusterfuck of bad UI decisions and insane defaults that one wonders how it's held its place as the king of vfx 3d for so long. zbrush might be easy to start with - it's like finger painting! - that's until you try to make sense of its million sub menus. My point is, blender just happens to trip you up right away with the clicking thing, and it's happened to me that I stumble upon that and I go "oh, this free software doesn't work, it's crap", so for sure it's bad marketing, but they are all the same in the end.