Just to add to what others have said
to the op- really you started out the worst possible way. By looking at free stuff you've seen the worst and probably had the least satisfaction of what the Roku can offer. With Netflix and Hulu I think you'll soon start ignoring the "free" channels. I don't know who said it originally but the old saying "nothing worth having is free" comes to mind. These shows have to be paid for and Hulu is how that is translating to the digital age. As for the negative reviews, well someone out there hates anything you can possibly think of. I use Hulu all the time and love. The ads are tolerable and sometimes informative and enjoyable and the price is kept low by them. Some people expect Hulu to perform miracles but realistically we are lucky the networks have allowed the ads to be as short as they are. Netflix is a little bit of a different bag. You start out seeing what they are losing and think you may want to cut it. Then you start finding more and more that they have that you like and month after month will put it off. Next thing you know you are watching Netflix all the time and cable none.
I think the biggest problem Netflix and Hulu have is perception. They need a way to show us what is relevant to each of us personally. Hulu gets flack because of the web only stuff. If they had a way to hide that from people not interested then it would go a long way towards making people like me (who refuse to watch TV at my desk and don't have a HTPC) happier. Netflix is ahead of them on that with it's recommendation system but even they have some issues.