[Yo-Yo]

Sony has on occasion had a winner:

Sony invents 3.5 inch Disk Drive

[supercat]

Sony has on occasion had a winner:

I guess Sony had learned from the Betamax that trying to be an exclusive supplier of something doesn't work if someone can come up with an alternative (Mr. Robertson and Mr. Phillips demonstrated the principle many decades before). And they weren't yet fighting themselves since they weren't in any sort of software business.

I don't like the notion that Sony can kill disks by remote control, but Blu-Ray includes that as a deliberate feature. IMHO, that should eliminate it entirely from consideration.