It is a lot of "flavor of the month" culture. Some people have 2 or 3 year spotlight and anything is possible in that time until a new flavor comes into the space. Good, talented people are passed over without being promoted for years, until they either resign to their fate or resign the company. The mass exodus creates a jolt and suddenly just about any random person in promoted for the next year or two. This happens cyclically once every few years. Lot and lots of fat in teams and the real workers have undue load.