No, because it's not designed to be removed:
Basically, you've discovered a workaround, and we can't stop you from doing it (because the web is inherently a lot more flexible than, say, a Java Swing application). However, by not showing that bar you're locking out the one piece of UI that we don't let you customize - which means you're pretty much on your own if something in your project breaks and you want to, say, log in or log out. Or see gateway status information. Or anything else that's in that bar. For putting a session onto a TV, it's probably not a big deal - but changing CSS files to hide it will affect all projects, so it's not something you should do lightly.
Again - we can't stop you, but we're also not going to support you if you do decide to start hiding first-party UI elements.