Kai Nacke has put together a guest post for the D Blog [1] on how he decided the time was right for a 1.0 release of LDC. The reddit thread is at [2].

[1] http://dlang.org/blog/2016/06/20/making-of-ldc-1-0/
[2] https://www.reddit.com/r/programming/comments/4oz8h9/making_of_ldc_10_a_post_by_the_maintainer_of_the/