listen up

Audience and screen size on different mediums.

Is this funny, or it just me?
In the world of web, when we have 25% of the viewers on a small screen, we accommodate to them. We base our site designs to fit to the weakest, least advanced of the population.
Yet in the world of TV, now that 20% of the market has wide screens, the networks are switching to a wide screen format. I sit there on my 32″ 4:3 TV, and stuff is cut off left and right.
Why is this acceptable for TV, but not web?