Perhaps a bad choice of words -- "implemented" would have been better.
If someone releases a good, commercial-grade browser that supports
stylesheets -- along with an easy-to-write stylesheet language -- then
I am sure this will become the dominant mechanism for doing layout
formatting. This has not happened, no doubt because inventing a
stylesheet language and writing processing software is a trifle harder
than adding a few lines to a tag processing engine. (I am assuming, by
the absence of popular and inexpensive web tools that do rigorous
SGML processing, that real SGMLized tools are not easy, or cheap, to
develop).
It also did not help (in hindsight, of course, where all things are
obvious) that HTML 3 placed formatting information both in BODY
attributes and stylesheets. For example, it seems both confusing and
counterproductive to propose a BACKGROUND *attribute* to the BODY
element, arguing that it is an interim solution until backgrounds
are supported by stylesheets (that was at least one of the arguments),
and to then not provide an alternative, non-stylesheet mechanism for
controlling text colors. Better to have never invented BACKGROUND.
Now we are stuck with it, and, to be perfectly frank, with TEXT,
BGCOLOR, and so on.
I have also used stylesheets (with arena), and they are very nice. But,
I don't use/develop them for production pages, as almost no one else
will see the effect.
Ian