Alternative designs come with their own problems or ugliness.

The ones that look like buttons give me the impression that it's a medical device and are simply too pronounced. I assume they are that beefy because they need to house the battery in the "head" but the "head and stick" design can have more elegant head since the battery is in the stick part. Since Apple was the first to have that design, they now pretty much own it.

I also suspect that the microphones work better with the head&stick design since the orientation of the mic and the proximity to the mouth is better.