Fort Lauderdale officer in trouble for ticketing doctor on way to deliver baby

Sounds like this cop was a real asshole, but what I'm wondering is why the doctor thought he should be able to speed in the first place. Presumably, there's a reason for the speed limit to be what it is. If it's dangerous for someone to go faster just because they feel like it, then it's dangerous for someone to go faster even if they have a legitimate reason.