My experience at the office is different. I come from Java, but I've seen people who literally never programmed in Java or any other Java-like language succeed with Scala (and then they get horrified when they find out what Java looks like). They have none of the bad habits that come from years of writing Java code. It's enlightening, really. A few years ago this experiment wasn't possible -- of course everyone doing Scala was a Java expat. Not anymore, though!
I couldn't disagree more with you about excluding people. Excluding newcomers is always bad, but also, don't people "comfortable with advanced programming" deserve good documentation? Of course they can and will succeed in the absence of it, but only after wasting valuable time.
Linus' statement is controversial and shouldn't be quoted as gospel. In any case, he argued against C++ programmers because he thinks they -- and their chosen language -- suck, not because of advanced programming or whatever (note: not my opinion!).