It's not the best comparison, but it does have merit. Apple designs both the hardware and software - and the two should line up somewhat. Had OS X move more towards iOS 6 designs, I'd expect new MacBooks to look like hardcover books when I buy them.
Not possible. In this "post PC" era, OS X is no longer the main event. It needs to pair and keep up with iOS in terms of development, and the mobile space moves too quickly for Apple to sit in a two year development cycle.
On another note, aesthetics aside, have you guys actually tried focusing on your work flow to see how the new changes have either increased or decreased your productivity or enjoyment of the device? Sure, we can sit back and scrutinize every pixel on the device and of icons if we want to, but ultimately, that isn't what makes an OS great. Maybe 500 people will do so a few times a year, but the rest of the users are using OS X because it flows well, not because icons in System Preferences look a certain way better than other OS'es.
I for one can say I really like Yosemite because the new changes are nice. The UI/UX changes are different enough from Mavericks to feel new, but minimizing the top bars on several of the windows so we can focus on content is also welcomed. If you work in web, you may be irked that Safari now only shows the domain name by default, (I am), but at the same time, showing only the domain for most of the users provides them just the info they need to do what they need to do. Consumers just want to know where they're at, not necessarily what part of the building they're in - and it's touches like this that boost productivity just a lil bit for people that I appreciate.
They added a new option to show full web address now since dp 5 or 6. I prefer to just see the domain, it's so much cleaner. If I want the full web address all I have to do is klick on it and I will see the full address. Never got why people are so annoyed about this.