[Not sure what the right module to file this on]
As stated in issue 37943 the notion of "customize"
is used inconsistently in the IDE.  Almost all of
these cases can be presented in different ways
that are more consistent with the rest of the
interface in the IDE, and this is beneficial for
the users since they don't have to try to
understand this inconsistent "customize" notion.

The filesystems node has a menu item called
"customize" on its contextual menu.  It would be
desirable to remove it.

As far as I can tell, this displays a dialog which
lists all the hidden and non-hidden filesystems
and allows you to tweak the properties associated
with each.  If this is an accurate description,
one possible alternate design would be to remove
the "customize" menu item, replace it with
something like "Show|Hide Hidden Filesystems", and
then ask people to use the property sheet
associated with each to change their settings. 
This does make it more difficult to make many
changes to the set of filesystems, but I assume
this is rarely done and this design has the
benefit of not asking users to understand what
"customize" means, and removes a dialog that
doesn't have to be tested in the future!