So, you like Apple denying user's access (for all intensive purposes) to their own library folder Holder of app prefs, user brushes in Photoshop, etc. etc?
This is not exactly true. Let me try to explain some stuff that is going on.
If you have used Windows before you might notice that there is a folder in "My documents" that is hidden. Applications use it to store their data. I believe versions before W7, it was called "Application Data." On Windows 7, I believe, it's called "AppData."
If you have used any Unix system (including Linux and Mac OS X), you can find a lot of hidden files that have application configuration files (and other stuff) that are hidden in from the user. They usually reside in your home folder and their file names begin with a "." (a dot). When the first character in a file is a dot, that means it's a hidden file. Have you seen the file .DS_Store in pretty much any Mac folder? That's a hidden file used by Finder.
What Apple has done is make the library hidden. That does not mean you cannot access it. It just means that if you don't need to access it, you wont even see it. As pretty much anything in life, hidding files/folders have their pros and cons.
One of the cons is that it will take 1 or 2 extra steps to access it unless you create a shortcut to said folder or unhide it. (remember most app pref files are usually better left alone or edited only using said app)
Some pros are: A user that doesn't know what the folder is wont try to delete it, clearing all his configuration files and what not. Another pro: as most of these files are not used as much, you don't have to see them every time you are looking for stuff using finder.
If Apple has done anything wrong was to encourage developers the use of the Library folder as a dumping place for files that should be placed in a different place. (this includes fonts imo).
The best thing that can happen to the Library folder is for it to become a place where only configuration files are stored. That way, it makes transferring your configuration files to another machines fast and easy. I think with this change, Apple is now encouraging developers to only store the app prefs in the Library folder and the rest of files somewhere else.
If the folder where brushes are located is used a lot, then the better solution would be for Adobe to change the location of said file. Even if they don't, it's not hard to get into the Library folder in Lion. Probably Adobe would just post a how-to on accessing said folder.