There are a number of reasons for that: Perpetual Innovation Machines tend to wind down because there is no universally good search. Computers are powerful because they have limitations:
At Science earlier this year it was claimed that Darwinian evolution alone can make computers much smarter. As a result, researchers hoped to “discover something really fundamental that will take a long time for humans to figure out” …
We caught up with computer programmer and philosopher Jonathan Bartlett and asked what he thought of the chances of somehow stumbling on complex artificial intelligence this way. He said,
“The interesting thing about this paper is that it shows that the principles demonstrated in the 1990s by Wolpert and Macready still have not really sunk in yet. As their “No Free Lunch” theorems point out, there is no universally good search through any search space. This is similar to the question of perpetual motion machines, but the results are actually much more solid as they rely purely on mathematics.”
He pointed out that Eric Holloway’s recent post here at Mind Matters News on the word ladder game illustrates the problem very well.News, “Can AI really evolve into superintelligence all by itself?” at Mind Matters News
See also: Evolution and artificial intelligence face the same basic problem Eric Holloway: Think of the word ladder game, where we transform one word into another by changing only one letter at a time. Without knowledge about the goal and how to get there, it rapidly becomes first difficult and then completely impossible to reach the goal.