Rofl, I love how you're trying to link taste and personal preferences to IQ. It's the same mentality that all teenagers go through at some point in their lives: I'm right and everyone else is stupid and wrong.
iOS 7's design is a bit of an acquired taste and has been far less popular thus far than iOS 6. It's not about the flatness as much as it is about the loss of skeuomorphism. A lot of people hated skeuomorphism too, but the fact of the matter is: it made the phone feel familiar. The first time somebody picked up an iPhone using pre-iOS 7 software, they automatically knew how to access and use most functions due to their ability to link phone graphics with real life tools. It was super intuitive.
iOS 7 got rid of skeuomorphism entirely, which was the point of the redesign, but they needed to draw a line and they didn't. You can still do a bit of skeuomorphism with flat design to keep the familiarity, but the brilliant team of "a lot" of designers couldn't do better than thin blue text on a white background. The result is a confusing, space-wasting, frankly ugly experience that begs questions left and right about why they didn't just keep a touch of intuitive buttons and familiarity in their OS instead of going to the other extreme and making everything totally foreign for the sake of removing all traces of skeuomorphism.
Not only has Apple removed 6 years of familiarity and brilliant software design and engineering, but it has made a ton of poor decisions that made it hard for people to like iOS 7:
This obsession with white everywhere is ridiculous. The thin font is ridiculous. The slow animations that take a few seconds when you unlock the phone for the sake of showing off is ridiculous. The calendar app pre-7.1 was ridiculous. Replacing buttons that induce familiarity with thin text is ridiculous and space-wasting. Vastly reducing the amount of drop shadow on the icon labels on the home screen is ridiculous and makes it hard to read anything when using bright wallpaper. The list can go on and on and there are a number of blogs out there that actively point out design stupidities with iOS 7.
With iOS 6, the biggest complaint seemed to be that it had stayed the same too long. But even then, iOS 6's design was carefully planned out, carefully executed, and planted a feel of solidity and cohesion in the software. iOS 7 takes a massive step back and just feels like a whole lot of "we don't really know what we want" mentality behind a lot of the design aspects. Removing the linen everywhere was cool and all, but white everywhere is just lazy and I wouldn't at all call it an improvement.
So the main flaws are: it affects readability, affects familiarity with the software, is too harsh on the eyes with the white background and the thin font, impedes workflow with crawling slow animations that exist merely to show off, and is very inconsistent throughout the operating system. This is just a mere summary of the issues underlying iOS 7.
People can have an opinion about design. You calling each and every one of them stupid is just silly and you should probably try to find a new argument.
good job knowing nothing about it.
