I reckon you're probably right - it can be
very effective for some businesses (eg "here's some video footage of Bonzo, an incredibly cute puppy who came to the shelter six months ago after nearly being drowned in a sack with a brick. Help save puppies like Bonzo. Give us money.") but for enterprises that are, um, less visually appealing, it's less relevant.
The tutorial aspect depends on whether your customers really need tutoring. Google use tutorial videos quite effectively, but then, you do need to learn how to use a Google product and lots of people still aren't confident to learn by trial and error.
And a rubbish video is almost definitely worse than no video at all. Does everyone remember
WebCameron?