This has absolutely nothing to do with who you're aiming at and everything to do with our general tendency to speak way too fast publicly. As a techie who has given talks that was a professional actor for many years as well, I can tell you, with confidence, that "slow down" is just generally good advice for absolutely everyone who must be on stage in front of a crowd.

Some people are just fine and don't have to worry about this. However, for most people, even well trained stage actors, it is completely unconscious that you are speeding up and you will almost certainly not be aware when it's happening. So, if you just remember: "slow down" whether you feel like you're talking fast or not, chances are you're just slowing down to "just right."