Re: "It's the only thing that can do ALL the jobs at once. "
Ah, so you want me to buy a PC and dedicate it to watching TV, insert a device into it that receives TV, subscribe to a TV listings website to make the device work properly (or buy a pre-made PVR), and predict what I want to watch in advance (which I can't remember doing in the last ten years except possibly for Christmas specials, etc.). If I miss it, forget it, misprogram it, it gets rescheduled then I have to revert to my usual plan anyway. I also have to pay for local storage and (presumably) a UPS for anything vaguely important that I might miss. I also need an aerial with a good digital signal (don't own one, can't get one in my area yet) and/or a cable/satellite TV package. I have to tune yet-another-device in every time the channels juggle, have to have yet-another remote control, yet-another box on top of the TV and yet-more cabling behind the TV.
As opposed to:
Having an Internet connection.
Clicking on a website.
Clicking on what I want to watch on an official website provided by the original broadcaster.
(Optional, advanced extra: get_iplayer for permanent archives).
I have high-speed broadband for a reason, and it's not to send my email a fraction of a second faster. My ISP supports it and never has a problem and most IPTV broadcasts you see on your TV have been blatted across the Internet at least twice before you see them (footage colletion, editing, sending to broadcasters, etc.). Just because *your* ISP is oversubscribed, don't cry about how I should change the way I use my Internet.
On top of that - my PC plays DVD / Blu-rays, plugs into my TV, accepts remote controls of any flavour, has huge amounts of storage, etc. AND can do all the above already (even the PVR bit if I really want - £10 DVB-T stick!). I don't have to stick on a second device (third if you include the TV too) in order to watch something that I missed.
It's like saying to someone - "ITunes MP3's?! Why don't you just record the radio 24/7?!"