I also had that impression prior to upgrading to Yosemite. And it is somewhat true, but not as much as some of the tech blogs would have you believe.
IAC, there are settings you can make in System Preferences (and otherwise) to mitigate many of the Apple imposed styles, like transparency. Just do some searches on keywords like "upgrade mavericks yosemite" you should see a number of articles that help.
Since I upgraded from Mavericks to Yosemite about a year ago, I have NO regrets. And I hate the iOS UI style.
You might also be interested in this thread I started here just before my upgrade to Yosemite: