I think that plugins should be able to be totally customized by user.
However, your website only provides "bundled" downloads. I downloaded and installed 7.3.
I found that the pre-installed plugins are unable to be uninstalled, because the "uninstall" button are grayed for those pre-installed plugins.
Also, the platforms such as "PHP", "Java", and "C/C++" are unable to be added or removed. They are not easy for users to customize their NetBeans because there will have lots of plugins they do not need (even though it will be easier to build the environment sometimes.)
I found the alternative way for the two problems:
For the pre-installed plugins that can not be uninstalled, I deleted the package files in sub or offspring folders (like /ide/ /ide/modules/ /nb/modules/ /webcommon/ /websvccommon/) under the installation directory with NetBeans not launched. Then the plugins will be disappears from installed, and I can get any plugins I want without any pre-installations.
For the preset Platforms (Environments), I deleted the corresponding directory (often have same name as the platform, such as /php/) under the installation directory with NetBeans not launched. Then the platform will be disappears from preset platforms, and I think maybe I can get an platform from Plugin Manager.
That is how I manage to make a "blank" NetBeans for customize, but I think it is harder for any new users, would you like to make an "blank" download for users to customize any platform and plugins they want?
We offer NetBeans Platform which is the empty backbone you can fill with other modules. I don't think we plan to do anything else.
Talk to PM like Geertjan, if you want. I would personally close your report as won'tfix.