Frustrated by narrow text columns

Many web sites that provide textual information restrict the width of the text columns even if I have lots of spare space on my screen.

If I expand the viewing window width I expect the text column to expand also. Otherwise I end up with lots of wasted screen space, and having to waste time scrolling down (or up) the page to read more text. (Hmmm... I wonder if that seriously increases the risk of RSI?)

It gets worse if I increase font size (which I prefer to wearing my reading glasses). If the text column width is fixed, increasing font size means I get fewer characters per line (i.e. the line width is effectively shortened) requiring even more scrolling.

Why are there so many format dictators on the web?

Even the BBC does that: it is one of the worst. See http://news.bbc.co.uk/

Google news is much better in that respect.

If anyone can tell me how to alter these blogger pages so as to make the text column a percentage of the window width I'll be very grateful.
(You can email me at A.Sloman @ cs.bham.ac.uk -- thanks.)