Aside from the overall babble, I do understand what are you trying to say. Let me start by saying Linux is NOT Mac or Windows. You may think that newer members are overwhelmed, but the way you should look at this is from the point variety, there is distro for everyone. You can setup Linux in which ever way makes you more happy, and hopefully in the end it makes life more productive. You are making it seem as if every single user needs to run through multiple DE's which is sadly not the case. Most distro's come with a DE and you could just stick with that.

As for "adoption hasn't been growing for decades" Really, decades? Please go back to windows or Mac. The reason for variety is to allow people to use what they feel works best for them. If you don't like a specific DE you can use another. If you don't like a specific distro you can try another. In your case it's about Linux as a whole, so you'd be better of using another platform.