The PBE recently showed some changes for Vayne to impact her kit, both positive and negative changes that would change the distribution of power in her kit. The moment this happened, the floodworks on the forums started and tons of people who had never stepped foot onto the PBE were here to offer their two cents on why they would perma ban Vayne if these changes went live despite having no idea what the extent of the impact was.
Then the changes were completely removed from the PBE recently, and you know there will be vindication threads for all those complaint threads that were made, and people will rejoice and celebrate. But there's a disturbing trend to that I really don't like with public patch testing. And that's the idea that complaining about something rather than being rational and testing it seems to be the go to answer for people who are against the changes.
The PBE is there to test the impact of changes and see how those interactions work. Testing and seeing how things change is a vital part of League Patches and gives the developers insight into what their desired changes might look like and if they accomplish the goals they want. Game design is not an exact science, and sometimes testing the impact of seemingly bad ideas can actually lead to the correct outcome, sometimes tweaks can be made. Perhaps the problem with the healing on her ultimate would have been the amount, in which case numbers can be changed, but if the healing was problematic because it didn't fit the feel or accomplish the correct goals then it goes away.
These changes are going live inevitably, there isn't some kind of urgency for you to shout down the ideas before the game is ruined. I would NOT want League to become a game that gives in to the unwarranted forum outrage over changes that are still being tested and haven't even been cleared for implementation fully. And I really don't want vindication for people who blindly complain about changes because it gives strength to that idea and we will just have more of these types of threads as changes are posted to the PBE.
TL:DR - Stop being whiners and go test the changes before you make rage threads, because I don't want to see the forums devolve into nothing but rage threads and I really don't want to see Riot cave to complainers instead of being willing to test controversial changes that might be good for the game.