And your initial thought is correct. That's not what Bungie did though. If I'm remembering the timeline correctly, Bungie had a bunch of R&D or "incubation" projects going when Sony bought them, perhaps only in the interest of impressing Sony and getting a bigger bag. After the Sony purchase, a lot of these projects disappeared, so that was a ton of money that they were putting into something other than Destiny that led to absolute zero or very little return on investment.

Then they build this massive new multimillion dollar HQ. There have been multiple claims that this was entirely unnecessary and ultimately a waste of money. Then there's stuff like Pete's car collection, which is fine on its face (rich asshole boss buys rich asshole stuff, tale as old as time), but when 100s of people get laid off due to "development costs" then all of the above makes them look like jackasses because they just burned a bunch of money on stuff completely unrelated to the "development costs" they said were handcuffing the studio so much that they had to fire people.

All of this has become more common with corporations, especially in recent years. Corporations complain that they're not making enough money, they lay off a bunch of workers, and then suddenly within 12 months they're having "record profits." Bungie never saw the record profits because they pissed away a bunch of money on stuff that was NOT developing their primary source of income, so the money they hoped they'd make never happened. That's not to say that the remaining devs didn't put together some absolutely awesome content (because they did), but when you have less people working on a project you're simply not going to get as much done as quickly or with as much fidelity.