No. I don't believe on average a balor is going to be good as often as an elf or an orc. An orc is not going to be good as often as an elf. That does not negate free will so any given Balor in theory could be good though he'd die almost instantly when his fellows detected he was good. Personally as a GM, I am always open to a traditionally evil being being good for some unusual reason. Hey helmet of alignment change if nothing else. That does not mean I can't ever have a default view of a particular race or creature type for a given world.So do you believe a succubus or a balor has the same opportunity to be LG as an elf or an orc?
If you believe in angels and demons for real for example, then you'd think all demons are evil and all angels are good. I know not everyone does though so that is just an example.