I have enormous respect for designers, and I know full well that I, a programmer, can't do what you do and that anything I might produce that puts pixels on a screen benefits immensely from a qualified designer's input. That said, those are poor arguments.

1. Tough? Learn to think better. What would we tell a programmer who doesn't want to use recursion because they "think in loops"? What would you tell a carpenter who didn't want use screws to put your new furniture together because he "thinks in glue"? Units of measure are a tool, and your facility (or lack thereof) with a tool doesn't affect how good it is.

2. I actually admit to some ignorance about browser scaling algorithms, so you may be entirely right here. In any case, I think it's the least important of the issues at play.

3. I submit that it's more important to make sure that your users can use your websites in a way that's comfortable to them, rather than that they should be able to bask in the glow of your unsullied brilliance. I don't mean that I should be able to randomly change fonts around because today I like Georgia and tomorrow I'm going to like Chicago. I'm wondering what happens when your site suddenly starts getting traffic from Israel, and all your new users are using Google Translate to turn it into Hebrew. Not only do your font choices go out the window, but all your ragged right just became ragged left, and some page elements may have have spontaneously rearranged themselves. (See http://translate.google.com/translate?js=n&prev=_t&h..., for example.) Or what if some of your users are colorblind or elderly or dyslexic, or just have trouble reading your type selection for any of a myriad of reasons? Is it more important that your design should remain just how you like it, or that they should be allowed to read it? Before you answer, read this: http://tigerbeatdown.com/2011/07/14/harry-potter-and-the-oh-... It's not about web accessibility, but the major themes are still there.

One of the incredible things about the web is that not only do we have the power to make the content we're producing available to an extraordinarily diverse population, we have the power to make it so that they can all read it in a format that works for them, as individuals. When you have to design a poster that's going to get sent to a printer and plastered over bus stops, everyone waiting all over town is going to see the same poster. When you design a web page, everyone who sees it gets a separate stream of bytes and a separate display to see it on. Why not let each user find the best web page for them, instead of forcing them all to see the best web page for you?