I don’t see the style attribute on that element, so I’m not sure that’s what’s being stripped. If I view the page source I see:
<div id="article-content-bottom">
<p>Hartmut Steinert hat die Nase voll. Und sieht die Kommune...
Remember, if you’re using your browser’s web developer tools to inspect elements, you may see elements and attributes that have been inserted by Javascript into the original page source. Full-Text RSS doesn’t see any of that, so to see what Full-Text RSS sees, you should right click on the page and click ‘View Page Source’. Then you’ll be viewing the HTML as sent by the server without the Javascript that may be executed later on meddling with the page.
If I use Full-Text RSS on this page, that element is included in the output. You can test with our public version at http://ftr.fivefilters.org.