The Ubuntu community got so large because Ubuntu was something that people found very useful. Then a few years ago, questionable decisions started being made. They brought a very poor experience to a huge number of people, without offering any benefit.
The criticism is valid, and it should be voiced loudly and often.
It's not isolated to Ubuntu, either. There are other major open source projects that have started to actively defecate upon their existing user base. Firefox and GNOME are two big ones. We see the same kind of widespread, large-scale anger from their communities, too.
The leadership of Ubuntu, GNOME and Firefox have all chosen to essentially ignore the ever-growing disillusionment within their existing communities. I think it will cost them dearly. We've already seen a lot of people moving to alternatives.
More importantly, these are the power users who are moving away. These are the very people who are needed by any project that really wants to succeed. They're the ones who help drive others to use the given product. Without them, the project is nothing. It may take a few more years, but I do think that we'll see GNOME, Ubuntu and Firefox go the way of XFree86, if things don't change today.