Poor review of an excellent product
Firstly, let me state that I'm not a Moviestorm fanboy, and I agree with you that the UI is clunky, and the polycount (when compared to today's in-game graphics) appears to be quite low.
But I think you've misunderstood how the product works (it doesn't do everything online - it checks the status of your account when you launch it, and to check for any updates which can then be downloaded automatically. Other than that it runs entirely on your PC or Mac.)
Secondly, you include some links to a couple of machinima examples, but curiously nothing which has been created with Moviestorm - if you want to see what can be done with the software then check out "Incubus", "Saving Grace", or "Cafe Insomniac" by three of the most talented machinima directors- you can find them on moviestorm.co.uk, or on Vimeo.com.
For myself, I have no training in movie making, 3D modelling or the like. I started playing around in Moviestorm a couple of years ago as it emerged from the beta programme. Last year I had some of my movies playing in film festivals around the world, and not just machinima festivals. I've also had several screenings at film societies in the UK, and rubbed shoulders with "real" film directors. None of that would have been possible without Moviestorm, and this is the other point that you miss - apart from Moviestorm there are very few tools that enable casual users to create movies - tools that allow the director to concentrate on the content without having to hack into a game engine (not for the faint hearted!).