They lost money on the console itself, but were already profitable after accounting for software, accessories, and so on by 2008. [1] The console was released in late 2006 and was a beast of subsidization in part because of the heated blu-ray/hd-dvd war which now seems quite quaint. The modern business models are just really taking the consumer for a ride.
If either company maintained the previous business model, they'd have made the competitor look like a clown. It was basically a prisoner's dilemma, but they both chose to collude. It's hard to explain that without assuming that they're colluding, which is basically a tautology.
AFAIK the profitable quarters your link refers to were after they made all the hardware changes that rolled back the decisions we’re talking about. Wikipedia has many source about it from the main article and highlights the one you linked.
As an aside, I don’t really care about the collusion claim.
If either company maintained the previous business model, they'd have made the competitor look like a clown. It was basically a prisoner's dilemma, but they both chose to collude. It's hard to explain that without assuming that they're colluding, which is basically a tautology.
[1] - https://www.gamespot.com/articles/hirai-claims-ps3-platform-...