Most versions of the American accent are a bit nasal compared to other English speakers, so I guess that makes it higher pitched on average -- even if I wouldn't call it "shrill".
Also, there is no a neat separation between nasal Americans and other English speakers. Many Australians are also quite nasal, whereas black Americans (unless you count Steve Urkel) don't strike me as nasal at all.
On the third hand: I find the Irish accent is higher pitched than most, without sounding either nasal or shrill. But Americans often sound a lot like the Irish, so that might also make them higher pitched.
Now you are confusing me, because in Australia "mall" means something else -- and in Bondi Junction there's a mall right outside the Westfield.
I had some visitors from from Washington DC recently. They were impressed at how much more "happening" the local shopping centre (Hornsby Westfield) was compared to American malls. I suspect Westfield is a bit of a world-leader in this business.
I'm guessing you don't count cURL as half-decent. Because it's API is C++k let alone idiomatic, modern C++?