Well there is 198 pages...
Yeah but there is a search function and the question repeats every third page.
In a short, there is no enough development power (developers or developer's time.), and it is anyway not so important because M doesn't mean what most of people think it means. M doesn't mean bug free and stable, it means they try to focus on already present bugs, stop new code/feature merges, and in the this doesn't helps at all, because of lot of reasons. Like bugs are fixed in upstream, and upstream doesn't care if you have freezes the Branche, and just like M will import fixes, so will nightlies, together with new code, which can bring cool stuff + more or less bugs (which don't have to hit you at all.).
I hope I helped a bit at least. If not, it is not my fault... Maybe ?