What were people doing that got such a strong response?
I think social media and individual videos (like 2by2 Videos) being put on YouTube played a huge part in creating 'Cheerlebrities'. In my opinion, very few would invite the attention on themselves but people would identify an athlete (they usually had a certain 'look' that Tye Hill is referring to on his post) and latch on to them. They were usually (but not always) flyers and all very talented but the thing with the Cheerlebrity trend is that it became all about them and not their team.
There would be guest appearances, stunt and tumble clinics with the focus being 'come to our clinic because ______ is gonna be here!', meet and greets, guest judge opportunities, magazine articles, advertising cheer products like hairspray, segments on TV news and I vaguely remember a youtube series happening called Secret Diary of an American Cheerleader amongst other things.
It also led to mass crowds following these poor athletes around at comps and cheer anons analysing their every move (and fall). As we know, this unfortunately still happens today to certain athletes but although things like meet and greets still happen, the "Cheerlebrity" side of things has died down in my opinion.
Basically, a lot of these athletes became very popular in the cheer world and this popularity was then exploited by many companies and milked as much as possible. Whilst these were great opportunities for the athletes involved, it took the focus away from the team and isn't really what cheer should be about.
Erica E has a youtube video that explains her perspective of being a "Cheerlebrity" around the time where things hit their peak (pretty sure she was in the youtube series).
I don't want this response to come across as rude to the athletes involved because they did what they felt was best at the time, just trying to explain :)