So what's wrong with seeing pixelation on a digitally created image? It's a perfectly valid artistic choice, to allow pixelation as an intrinsic feature of the work.
Like I mentioned, I don't like the scaling effects. It's not just pixelation: browsers use nearest-neighbor scaling, which introduces defects that poke me in the eye.
Of course it's also a valid choice to spend a lot of time creating an infinitely zoomable vector-based image.
Huh?
For me, it was definitely faster to do Tux in Inkscape, than it would've been in Gimp or Photoshop.
I am not a graphic artist, but I do have done that work, too. For example, in 1997 I created the very first set of collector cards for the Finnish Defence Forces; purely PR stuff. Used a classic Mac for that: Photoshop (4.0, IIRC) for the photo editing and touchups, Macromedia Freehand (7.0, IIRC) for the layout and diagrams and text on the backside.
Do note that the SVG stuff is just 90k or so, and it is already loaded when the page loads; no separate TCP connection for the image. That means it loads faster than if the image was in a separate file. All in all, incorporating SVG into the HTML is simply superior to using a JPEG or PNG image instead, for this kind of content. Photos are a completely different matter, of course.
If I would get off my butt and implement it, I could make Tux have Crazy Eyes, following the mouse cursor, with just a few lines of Javascript on top.