Not going against Gnome here, but against your last sentence.
As long as they give the user the ability to opt out/in, what’s the harm in introducing it?
Pretty sure systemd did this with a lot of things and started removing things they just didn’t like. Can’t find the website I wanted to link, but it included a lot of reasons why systemd isn’t good (for example, binary logging. Why ?) “You can always opt out” doesn’t work in the real world ; people don’t care enough to switch. Why do you think google is the biggest search engine ? Mainly because it’s the default everywhere.
In this context I guess it doesn’t matter (and I couldn’t see myself using gnome, even if it has some good polish), it’s just that “you can always opt out” leaves a bad taste on my tongue.
gosling