Thanks for sharing your thoughts and bringing this to our attention! Who knows, you may see your suggestion implemented in a future update. You can check out our blog at http://blog.roku.com for the latest news and upcoming updates.
Re: Why hasn't Roku ever released a tablet device?
Roku is only getting into it's own TV's this summer. Right now, a Roku TV is actually made by a 3rd party, and just uses the Roku OS. With all the phones and tablets already out there, creating one exclusively for watching TV may not sell well. Plus, most of the services have their own apps for those devices anyways.