This here is a great example of why statistics should only be used by those who understand them. Otherwise- like in this instance- it's like giving an assault rifle to a chimpanzee.
Stats are great- I love them. If used correctly, with good, wide-ranging data, and proper analysis and filters to balance the effect of aberrations, statistics can be extremely useful.
But that level of maturity and subtlety is beyond a lot of people who pull out numbers from their butts and try to prove asinine assumptions.
If a guy made 10 semis and won all of them,
@ADuck would effectively rate him better than a guy who made 30 semis and won 25 of those. The 'Gosh how do people not get this' makes you look like somebody who just learned today what percentages were. Calm down.
The second part of your post- about 'fully expecting Rafa to win the semis he never reached'- is so ludicrously stupid that I'm not going to comment any further about it.