How, exactly, is it "horrid"?
No need to pull my words out of context. I'm directly referencing it for content creation.
It's funny, but every time I ask this question of the start screen haters, all they can do is mumble something about not being designed for a keyboard and mouse, which is patently untrue.
I'll tell you.
There are two halves to any piece of communication. Content Creation, and Content Consumption. I'll define.
Lets break back to pre-history. There are two guys.. one sings the other a song that he wrote in his head. The process of writing it is Content Creation, the process of listening to it is Content Consumption.
Both halves have evolved since the dawn of man. Someone figures something out, broadcasts it to another.. information is created and consumed.
Content Consumption evolved through the spoken word, through theater, through telegraph, through telephone, through radio, through television, through this thing you're reading my content on called the internet. I'm currently using a web browser to construct this content that you are now consuming.
Content Creation evolved through writing with and on objects(walls, paper, desk, typewriter, computer, etc). All Content Creation shares one similarity. It takes lots of input into an environment, and produces an output. If you're at a desk and a kid comes up to you and asks you a question unrelated to what you are doing, what happens? It breaks your train of thought. If you're sitting at your desk going through multiple files, managing photographs, looking at statistics and creating a concise report, what happens if you turn on the television? You lose your train of thought.
The walled garden style interface that Apple came up with is meant to evolve Content Consumption, not Content Creation. It is literally the next broadcast medium. Content Consumption involves 'flipping channels', and as such.. its natural to move from one consumable program to the next this way. Just like browsing websites.
What is *NOT* natural is to be trying to create something, and you 'turn on the television'(or hit the start screen button) to get another piece of information, and the entirety of your work goes away. Subconsciously, this is just like losing your train of thought. You now have to find the piece of information you want, while not keeping what you were working on close at mind. Don't try to pretend you're some master user. This is how it works. You are literally telling your mind to forget about what you had, and go get THIS. NOW. If the Start Screen were simply chromed, it has a different effect on the user, because you still see some of your work up on this screen. That signal to your brain is... you need this... grab it.. but don't forget where you were.
This happens *every* single time you run an app that sends you full screen and why it sucks balls for content creation. You subconsciously lose your train of thought every time you run one in favor of something that isn't that important, but the visual cue tells your mind its the most important thing ever. Its like working at your desk and turning on the TV.
For content consumption, I think Modern is as good as any other app setup. There is nothing 'horrid' about it. But content creation should never be broken thematically, and you should never use a content consumption medium to create content. This is the reason something like Google Docs sucks, but you really can't put your finger on exactly why. They take a content consumption medium(webpages and the internet), and try to turn it into an arena for content creation. To some extent you can do it, but it never.. ever feels 'natural'. This is the reason why.