Makes sense to spend $200+ on a game console to watch Netflix. :B
Only makes sense if you also play PS3 games. I doubt many on this forum play PS3 games.
I have quite a few different options available to me for streaming Netflix, I could run an hdmi cable from my desktop, laptop, netbook, Android mini-PC or my phone to my TV. I have a Blu-Ray player with built-in Netflix app. I have 2 Vizio Smart TVs with Netflix capability in my RV. Using my Chromecast dongle, I can use my desktop, laptop, netbook, phone or tablet to stream Netflix to my dumb TVs.
The desktop, laptop, netbook, phone and tablet all have their own screen so I could stream Netflix on them without hooking up to the TV.
There's probably more ways for me to do it but that's all I can think of at the moment.
The point is that Netflix is available on many platforms. Where a device like the Roku shines is that it has many channels in addition to Netflix.