The original purveyors of flat design were well intentioned. They based their designs on sound principles (simplicity, authenticity, mobile-first). They didn't

The original purveyors of flat design were well intentioned. They based their designs on sound principles (simplicity, authenticity, mobile-first). They didn't intend to have their designs turn into a rigid style. Other designers started to notice. People started blogging about the "flat design movement" (which didn't yet exist, but nevertheless made for a great headline). Some designers agreed with the sentiment and copied the style. Then, nobody could deny the impact of flat design. It was everywhere. But for every designer out there, there are hundreds of imitators. They call themselves designers, but all they know how to do is clone a certain look. They are like the skilled painters who make forgeries of famous paintings, but can't paint originals. They started copying the flat design they saw everywhere. Except they didn't understand the principles behind flat design. They used it where it was not appropriate. They took it to absurd extremes. They disregarded readability, usability, and originality in pursuit of a certain look. So now you have the same bad design everywhere. Design fads exist because most most web designers are really imitators. They don't tailor a solution to fit the problems. They are just good at imitating other people's solutions. And since most founders / bosses / HR people aren't designers either, the imitators get hired.