This all sounds plausible, but I actually don't buy any of it. An example anecdote: we gave our technophobic MD a desktop that had been used by a previous sysa

This all sounds plausible, but I actually don't buy any of it. An example anecdote: we gave our technophobic MD a desktop that had been used by a previous sysadmin add a temporary machine while he was waiting for a new Windows one. It was running Maté on Mint. He never noticed it wasn't Windows. The reason the Linux Desktop hasn't happened is multifaceted (as you contend) but by far the biggest factor is OEMs. Normal users don't know/care what an OS is, so they're certainly not going to install one. If you're contending that usability is a factor, look at Windows 8.0 or early Androids. There was plenty of complaints about both, mostly valid imo, but they still got a lot more new users than traditional Linuxes. Because people don't download OSes, they buy devices. And if they get stuck with one that's less than usable, they just stay stuck, and maybe get a relative to help. They don't switch. All the reasons you listed are valid and true criticisms, but the above makes them moot. The idea that fixing X Windows' complexities or unifying the community on a focused UI/UX vision will popularise the Linux Desktop is hopelessly naïve. You won't get far without a device manufacturing operation and billions of dollars.