I guess the answer to that question is nausea?
Again, I changed my iOS (I refuse to call it an upgrade) with all trust and faith in Apple that it would be an improvement, like previous upgrades. I knew there would be elements I didn't like, but I figured I would get used to them and that the improvements would make up for the bits I didn't like. There are many, many bits I don't like, and who knows if I would get used to them, but the fact is that it is so unpleasant to use my phone now that I'm not on it enough to get used to the garish colors and unreadable fonts. Because it makes me feel sick. And I have sent them feedback, as have probably thousands of others.
Apple fanboys can call us liars and Apple can ignore us, but the fact is, there are alternatives and if it's their choice to drive us to those alternatives, so be it.