Just Wondering

How does anyone watch a movie on a laptop (unless they're stuck somewhere, like on a long plane ride)?

 Artist's depiction

I just don't get it.  I keep reading comments on blogs like this one: http://www.unplggd.com/ from people who insist that they watch all their TV on their laptop or desktop computers.  Isn't the picture too small, especially for more than one person to watch?  And how do you get in a comfortable position to sit still and watch anything that long?  I can't watch anything on my PC for longer than five minutes. 

Don't get me started about watching TV on an iPhone!