I know it's all at least semi- tongue-in-cheek, but IRL a piano's discrete, sequential keys are what make it almost inarguably the easiest instrument to learn.
That's exactly his point. Languages aren't easier to learn simply because their specification is short, any more than instruments are easier to play because they have fewer strings.
The analogy is completely invalid. Languages with small specifications are easier to learn.
It's sad that the dev, who has done great work, has to spend time defending the C language from critters living under a bridge when it's a fixed element that isn't going to change.