I'd like to start a fundamental ongoing discussion about the future of WordPress, since it is the dominant platform for site development in the world today. I think a big issue is bloat. As web developers we learn to code efficiently from the ground up, to make things fast and efficient and clean and orderly.
Having done dozens of WordPress sites now and torn apart many themes to give people what they want, I am constantly amazed and dismayed by how astronomically bloated the CSS in most themes is. I know each theme varies according to the complexity of the design and feature set, and the coding style and ability of the author, etc. but the themes don't exist in a vacuum, and the fundamental architecture of WordPress certainly plays a significant role. In some themes just the comment-related styles alone are more verbose than all the styles that I might write for an entire static html site.
Take a popular, simple looking theme like 2012. To be blunt, the CSS is an absolute abomination to someone who loves CSS and values clean, concise coding. That's not meant to hurt the author's feelings, but I think it's undeniable. CSS being my strong suit I have no trouble accomplishing whatever I need to with a theme like 2012. I can make it look like pretty much anything in a few hours, but it's still horribly, horribly bloated, and to a novice CSS person it must look like quantum physics.
I'd like to see a future where WordPress cleans up its act considerably in terms of architecture and efficiency.
One partial solution would be a dynamically linked system where function and corresponding styles are linked, users/developers are able to easily shut off parts of the WordPress feature set, and the style.css is revised and pared down dynamically, accordingly.
WP would establish a system of describing and delineating the components that account for various functionality, theme authors would be able to hook chunks of CSS into each, and then end user (the person implementing the theme) would be able to reel in the CSS, and the overall efficiency of WordPress in general, by shutting down all of the parts of WP they don't want to use (without editing PHP), and the css would be pared down accordingly.
Why not just ignore it? Well, it all has to be checked by the browser, but that's not really the point. I think the question is can WordPress ever be lean? I'd say in the current paradigm, no, never. Perhaps we need an entirely different version that focuses on speed, simplicity, and efficiency. I think so.