I use them for preserving man page formatting _^HX_^HY_^HZ gets translated
to <I>XYZ</I>. If you don't like them and believe they are void of content
then simply ignore them in your browser. I believe that since HTML is
more of a delivery vechicle than a formal markup language they are required
because HTML cannot be all things to all people. I VERY much agree that
tags should be semantic but in a delivery format I think you need to leave
a little room for slop.
If you remove <I> and <B> what will happen instead of using TeX or whatever
people will use stuff like <CITE> (or whatever formats nice in their browser)
where it is inappropriate (assuming you removed <EM> and <STRONG> for
the same reasons).
If you resort to an external format how are you going to deal with hypertext
links? I may not be able to figure out why foo was in italics but I can
sure as heck generate a hypertext link to man pages from text like
``foo(1)''.
--sanders