What sad news, sad because it seems that the real reason is the shortage of personnel to develop ROMs for so many models and can not cover such amount of work with a minimum of guarantees. I like your honesty for, at least, guaranteeing a stable ROM, my experience and that of friends familiar with MIUI since its inception we know that "Always", "Always", Betas has worked better than the so-called "Stable", Yes in a Beta there were errors the following week they were corrected and if in a Stable they appeared bugs, they were serious or not, they permenecieron during weeks because neither the calendar of updates of the stable ones has ever fulfilled. This situation and not another is what forces users to switch to betas ROMs, because many times those errors prevented us from enjoying our mobile.
I understand that you can not tell us the true reasons for this decision, which of course I guess it has not been yours, but please at least do not treat us as children to the users that we have always trusted you to make things better for we, who after all are a legion of fans and these changes (and previous) do not improve at all our positive perception of the brand.
I want to insist on thanking you for your honesty for your effort in working to provide us with stable ROMs that really work well.
The pity is that instead of putting means so that the experience of the user is optimal it is easier to trim them and by that way badly we go, very badly.