It is also often pretty evident that C++ induces people to obsess over performance bottlenecks that were relevant on 80's hardware and while doing so introduce another (often more severe) bottlenecks relevant for modern CPU's. See for example C++ developers affinity for inline functions and templates expanding to huge amounts of inlined code, another common belief is that there is profound performance difference between virtual and non-virtual methods.
Do you have evidence that there is not a profound performance difference between virtual and non-virtual methods? Virtual methods require two memory lookups (the vtable address, then the function address) and hence often two cache misses, compared to non-virtual methods which can be static addresses. If you've got a (common in games) loop like:
for ( ..some list of 5000 objects.. ) {
object.update();
}
Then those cache misses will add up. That is my experience anyway, though I'll don't have statistics to back it up
