Yes - the practical reason is to focus on the newcomer's experience. Information overload is actively harmful to someone coming to haskell.org to learn about the language from scratch.
Omitting content that is primarily valuable to experienced Haskellers is a feature, not a bug.
This sounds like a dangerous trade off to be making. It's reminiscent of what we saw with GNOME 3, or even Windows 8. The experience is made much worse for existing users, in a vain attempt to "simplify" the design to allegedly appeal to new users who may not even really exist in practice. It's obvious now that it didn't work well in those cases, and I don't see why this case would be any different.
As an occasional Haskell user, I'm served much, much better by the existing site than by this new design. The existing one lets me get to the information I'm looking for with minimal effort. This new site denies me that accessibility, I'm afraid to say.
I don't see the point in trying to attract new users if doing so also means harming the experiences of established users. Drawing in new users becomes pointless if retention starts to suffer.
This case is different because it's an introductory page rather than a tool intended for heavy daily use, like GNOME or Windows.
Newbies are going to head to haskell.org when they want to learn about the language, and it's sensible for them to be greeted by a pleasant introduction to the language.
As "an occasional Haskell user," you aren't the target audience for the haskell.org landing page. :) If you're visiting on a regular basis, there's no reason your needs couldn't be met by some page other than the landing page.
"This sounds like a dangerous trade off to be making. It's reminiscent of what we saw with GNOME 3, or even Windows 8."
It's also reminiscent of what we saw with the iPhone, and nobody would say that the experience was much worse for users of previous smartphones. There are times when simplifying and giving structure to existing content just makes sense.
I'm curious, what content do you miss from the old page that can't be found in the Community or Documentation sections in the new design?
I'd like to see the Documentation, Community and News content on the front page, rather than hidden away on those separate pages. The new design adds an extra, unnecessary level of indirection in order to get to this useful information.
Fair enough, but as other posters have noted there's no reason why those contents need to be placed directly at the home page; they could be located at an inner page that you'd bookmark for reference.
The purpose of a good landing page is not to serve as an index for all the content (that's what site maps are for), but to explain the concept and structure of the site to someone that haven't seen it before. The new page is much better in that respect.
I miss a link to the current Haskell wiki in the new design, but I definitely wouldn't expect to find a list of all the wiki pages on the land page, but available under the Documents section.
I don't want to deal with numerous bookmarks to internal pages, or site maps, or any crap like that.
I want to be able to type "haskell.org" into any browser, and from there be able to quickly get to the standard library documentation, to the language spec, to Planet Haskell, to the downloads, and so on, without having to dig through subpages of subpages of subpages, and without having to scroll.
The Rust website at http://www.rust-lang.org/ is a good example of how a programming language home page should be laid out. There are many relevant links at the top. I can almost always find what I want within the first inch or two of the page. Yet it still shows all of the marketing junk for those who want that stuff, but it's placed well below the useful content.
The new Haskell design is the complete opposite of that. It puts a lot of useless junk front and center, and almost totally discards everything that actually is useful.
i don't think you can speak for all gnome 3 users. I'm the happiest i've ever been with gnome 3. I don't have a bunch of options and other knobs to twiddle. It just works and stays out of the way.
Omitting content that is primarily valuable to experienced Haskellers is a feature, not a bug.