Desktop Linux isn't really that difficult. It could be easier. The thing is that the people who want "really easy" probably aren't going to bother installing any new OS. Microsoft and Apple work hard, not just to make their OS easy but update their OS to whatever random hardware or software thing has come out (games and printers, say). Not being able to do "this one thing" is the main complaint I hear from friends who randomly wind-up with desktop Linux from computer recyclers mostly (it's my complaint too at times).
Also, elementary OS looks a lot like the "gnome shell" and latest Ubuntu thing. Mint/Mate has become the main Linux shell by staying with Window 7-like-shell. The newer shells are easier but less powerful. So it would win for those who want easy. Except those who want easy will do nothing and stay with MS/Apple. After they are "free" too or seem like that to the average person.
In what way has Mate become the main Linux shell? It’s not the DE of choice for the most popular distributions so it likely doesn’t have a lot of exposure among Linux environments.
Also, elementary OS looks a lot like the "gnome shell" and latest Ubuntu thing. Mint/Mate has become the main Linux shell by staying with Window 7-like-shell. The newer shells are easier but less powerful. So it would win for those who want easy. Except those who want easy will do nothing and stay with MS/Apple. After they are "free" too or seem like that to the average person.