It sounds like they are starting to move in a direction to capture my attention. I use a 4G Eee PC, and what do I do half the time with it? Pull up Netflix or Hulu in full screen mode - and I use cellular broadband to get internet on the go. (Other half varies, from research papers to general internet browsing to checking emails to a quick simple game.)
Am I going to reject it just because it cost over $300? Will I opt to get a full laptop instead? No. There are other factors that come into play.
Battery life of 6 hours is usually a lot better than any $400 laptop I can find. Size is also an issue. Although you personally may prefer a bulky laptop, I may really have a maximum size and weight requirement - so that means many cheap laptops are out. Then there is the noise factor. Sure, my Eee PC with EEECTL can make quite an annoying high pitched whine with the tiny fan in it, but that is far quieter and less disturbing than my tablet PC's hoover-ish whooshing. (Oh, and with EEECTL, I can push extra power into my screen brightness, allowing me to use a 'wimpy' 4G in FULL daylight!)
Now, for many, choosing a netbook in the $350 to $500 range doesn't make sense, but that does not mean it is an unwise choice. Some people need only analyze on price/performance ratios, but some people have different concerns and priorities that mean they need to consider more expensive alternatives. After all, computers are like any other high cost goods we buy - dish washers, washing machines, cars, houses, and so forth - different people have different needs, so a diversity exists in the market to meet them.