Earlier quoted context omitted.
I'm no expert, but just because it's used by professionals doesn't mean it's not a vanity brand. See Monster Cables and Beats by Dre.
It's losing some popularity now that companies like Arri are making better cameras, but that's been an industry leader for years... Any DP would be insulted by the accusation that RED is a "vanity brand."
I only learned about RED after all the hype with their first digital cameras (that all the studios were helping to hype)