Ego branding for the sake of hiring egotistical developers and analysts. Therein lies the rub.
A "rock star" can be a real thing. It could be someone who continually, and repeatedly, produces great work that impacts the entire community. These people exist most don't want the branding. But companies can't hire them; they're too expensive.
So the "rock star" became the one-hit wonder person. Someone who released a nifty script on github and gave a con talk on it. Two years ago.
Slowly, over time, that rock star status has turned into "most influential". That is, those with the most twitter followers, regardless of how good they are at their craft. Don't know anything beyond basic Ruby coding and lack knowledge of security programming... but have 50K followers? Rock Star! HIRED!
Considering oneself a rock star in order to apply for such a job breaks the whole "No Asshole Rule" for hiring.