To elaborate on the float example, see JSON, where text-based representations of numbers has led to massive incompatibilities among different parsers and generators. The original "spec" didn't even define if numbers were doubles or infinite precision or what. This is much harder to mess up with a binary format.
Programming languages and intermediate representations are about a lot more than representing floats. I think that it’s true that the best specification for how to store floats is a binary one. But programs have a lot more than just float literals and text wins at most of the other ones.
http://seriot.ch/parsing_json.php