I've also heard of people getting flat tires with every car ever manufactured on the planet. If every Netgear had problems, then they wouldn't continue being in business. What your friend really should do is go out and buy one of each make and model of wireless router available, set each of them up one by one in the same location, and then report back for which one worked for him. It would be a more practical, authoritative discovery, than to simply say all Netgears are junk and still not have a working solution. Channels 7 and 11 are the most common in use, with the most interference, because those don't overlap the other channels - it might make more sense to run through each channel available and figure out which one is best for his situation. And I don't see why people everywhere continue to be surprised when they call the manufacturer for help and are given billing terms for support - one of the reasons your router you bought is as inexpensive as it is - is because support isn't free. Reading the manual will (in most cases) allow you to troubleshoot and fix most problems you will face.
If there is any signal strength, it should be able to connect, just the speeds won't be where they could be - most likely it is either connecting and then dropping due to poor signal strength, or some other 'feature' is blocking access like the router settings, the mac authentication, the dhcp or other issues. But I'm sure you know Roku isn't responsible for your internet connection or router - you are. What makes this a "Roku developer problem" is beyond my comprehension. I have four rokus using a Netgear router - currently using channel 7 simply because it's cleanest where I am this week, haven't had issues over 60 feet from it with any wireless devices, and I have other devices wired. I'm sure other owners have similar 'stories' of reliabilty and tales of satisfaction with the product.