Right. But if someone wants to learn how to do it correctly from the beginning, instead of learning the easy way first only to have to relearn it later and make up for past mistakes, it does't take much more effort to learn how to use relative sizes. For one thing, it's very easy to avoid (or at least minimize) the nested elements problem by setting sizes as I suggested above (and again here):
body {font: 0.84em/1.3 Arial, sans-serif;}
* {font-size: 100%;}
h1 {font-size: 2em;}
h2 {font-size: 1.5em;}
h3 {font-size: 1.33em;}
h4 {font-size: 1.1em;}
h5 {font-size: 0.9em;}
h6 {font-size: 0.75em;}
pre, code, tt {font: 110% "Andale Mono", Courier, "Courier New", monospace;}
small {font-size: 85%;}
big {font-size: 115%;}