Salesforce is phasing out the use of arbitrary HTML on Home Page Components. I have used CSS or JS solutions to hide the Chatter Feed from within a HTML Home Page Component. This allows a more completely customized Home Page solution. (Especially elegant using Skuid to customize the page)
After Summer15 the only available component for customizing the home page will be a VF page - that will be nested in an iFrame. This makes it impossible to include code that affects the rest of the page - like the chatter feed.