Why are SPSite's, SPWeb's and SPList's UserCustomActions empty when a custom action registered via a feature's elements.xml?

I made a feature that installs a custom action via an elements.xml file (installed and activated it in a SPWeb).

<CustomAction Id="ChangeBrowseTabTitle"
            Location="CommandUI.Ribbon" 
            RegistrationType="List"
            RegistrationId="100"><CommandUIExtension><CommandUIDefinitions><CommandUIDefinition Location="Ribbon.ListItem.New.Controls._children"><Button Id="Ribbon.ListItem.New.RibbonTest"
              Alt="Test Button"
              Sequence="5"
              Command="Test_Button"
              LabelText="Import"
              Image32by32="~site/SiteAssets/EM.SharePoint.ImportList/fileimport32.png"
              Image16by16="~site/SiteAssets/EM.SharePoint.ImportList/fileimport16.png"
              TemplateAlias="o1" /></CommandUIDefinition></CommandUIDefinitions><CommandUIHandlers><CommandUIHandler Command="Test_Button" CommandAction="javascript:alert('That's me!');" /></CommandUIHandlers></CommandUIExtension>

Then I ran a console app that checked all the

• SPSite.UserCustomActions
• SPWeb.UserCustomActions
• SPList.UserCustomActions

in a web, where I registered the custom action.

But all the UserCustomActions collections are empty .

Did anyone encounter such a magic?

(The test was made on SharePoint 2013 Foundation October'13 CU).

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