And here comes my big 'ole list of imperfections in humans (copyright 2005):
The appendix serves no purpose and can, in fact, be deadly.
The human spine is rather poorly-suited to the way humans stand/sit.
The human eye interferes with it's own operation.
Human eyes have a fairly large blind spot
The human brain is prone to making up things that just don't exist.
The human brain is prone to turning random noise into images/sounds.

The list goes on. Humans are far from perfect.
No matter what humans were like this would be the case, if we lived on Venus you'd still be making this argument, so it really just doesn't work.
Only half of evolution is random chance, the second half goes and selects what works.

To use an example I've used before:
Let's say you meet a man who claims to have flipped 1 000 coins and that all of them landed heads. This is amazing, in fact, the odds against it are 1 to 1 x10^301. However, you then watch him in action and see that he flips 10 coins, he then goes and looks at them, any coins that landed tails or on their sides he removes, only keeping the ones that landed heads. Now the situation has changed, the odds of him getting anything but heads is essentially nil, it no longer seems so amazing.

It's the same thing with evolution, sure the mutation part is random chance, but only the good mutations survive.