The visual noise complaint is interesting. Do you also consider the letter W to be more noisy than the letter V? Should we discourage the use of noisy letters in the alphabet?
The difference is that " and ' are equally usable options in the context we're talking about. Quotes are very common, so the visual noise adds up when your screen is full of quote marks. Given that they mean the same thing, and one is both harder to type and harder to read, it makes sense to prefer the other.
Nailed it.
I thought the same. I guess you could just modify your programming font to make the double quotes really tiny :)