What I've seen play out time and time again is that a company with a good product goes public or gets purchased, and then their good product gets worse. Often much, much worse.
As a customer, I don't care why this is, but it is. That's why this is bad news every time it happens -- it's not that corporations are bad, it's that the products very often (but certainly not always) become undesirable.
To be fair, I think a lot of the time a company's initial product is developed/sold in a way that is unsustainable for profitability, in order to attract users/customers/etc. Think "growth hacking", etc. By the time such a company is bought, it's already at the point where they need to start focusing on long-term profitability anyway, which means cutting costs and actually finding a plan to make money. This always needs to happen eventually, and typically being bought (or IPO'ing, etc) is an impetus for this change.
I'm sure that's the case a lot of the time. But, as I said, as a customer I don't care why this effect happens. Regardless of the reason, events such as going public, etc., still mark an inflection point where the odds are decent that the product will become much less desirable.
But, as long as we're talking about possible causes, that startups do this sort of thing (catchy name like "growth hacking" or not) is a kind of deception that I object to anyway.
Releasing a product is a kind of promise, in a way. If a product is being released in an unsustainable way (growth hacking), the company should be calling that out from day 1.
As a customer, I don't care why this is, but it is. That's why this is bad news every time it happens -- it's not that corporations are bad, it's that the products very often (but certainly not always) become undesirable.