Because the problem is complex and your clear, simple solutions has at least 3 knock-on effects, one of which will make the original problem worse. And the other 2 will cause new complex problems in 10 years time.
The clear, simple solution to "X is to expensive" is "Declare a cheaper price for X by government fiat."
By the time you have compensated for the knock-on effects, regulated to prevent cheaters, and taxed to pay for costs, the solution is no longer simple.
People want to tell everything instead of telling the best 15 words. They want to learn everything instead of the best 15 words. In this thread, instead post the best 15-words from a book you've read recently (or anything else). It has to stand on its own. It's not a summary, the whole value needs to be contained in those words.
I'll start in the comments below.
(Voted by the Schelling study group as the best exercise of the meeting.)