you can watch any content on hulu at any time.
you're correct about this. you can't watch content on hulu that is not on hulu.
and what you watch with it
you can run hulu full screen on any computer with a web browser and flash. doesn't seem very limiting to me.
I'd rather a simple purchase/rent model myself
would you really be willing to pay for every tv show you might want to watch? i certainly wouldn't pay to keep up with half the stuff i have subscribed on hulu.
one of the things i like most about hulu is finding new shows and being able to watch an episode right away to see if i like it. all it costs me is a minute or two of commercials, during which i'm not likely to pay attention anyway.
ad-supported viewing is still viable, though it's not going to fail because of individuals like you. it's only going to fail when people tune it out well enough that these typse of ads no longer generate a good ROI. in the meantime, try to enjoy the free video streaming while we have it.
if hulu disappears, we're unlikely to get anything better in it's place.