Every job I've ever had started great with a small team who was actually interested in the company and its goals. Then eventually the company scales up, gets acquired, or IPOs or some other sign of maturity and a new group of leadership is brought in from a legacy/Fortune 500 type of company. That new group of leadership brings their own cabal/clique and they only promote themselves and start slowly pushing out the original employees and workers who got the company to where it is... the smart people see what's going on and move on to other companies as it slowly becomes hijacked from within and at the same time 'matures' and becomes a slug and incapable of improving or adapting.
Are you sure you're not just seeing the transition of a company from a growth company to a value company? I.e. "there is no growth potential left. Let's dump it on the public", and then a new leadership team comes in slashing costs to juice profits, because there's no way to increase revenue. Because that's certainly a phenomenon as well.
That's definitely part of it, but I've noticed there's almost always a shift when companies get to a certain size and start bringing in leadership in waves from other companies and it really changes the culture and dynamics of how the company functions--usually not for the better.
