Yeah...... Catch cans are expensive and complicated. The cheaper approaches require the owner to monitor and drain the can, which simply isn't going to happen on a typical production car. Or they would have to fully integrate it into the engine like Volvo does, but that requires quite a bit of specific packaging and design to make it work. Which is expensive. OEMs are extremely money driven. Don't be fooled otherwise. If an accountant determines that the potential increase in warranty work costs less than the delta production cost, then they're going with the cheaper design. Why do you think the front end of the stinger has struts?!
And the OEMs aren't convinced that intake valve deposits on a GDI engine are a problem. Doesn't mean they're right. This is the kind of thing that will take years to really show. Sure, they do lots of testing, but it's focused on economy and warranty claims. Just like transmissions with "lifetime" fluid. Doesn't mean the fluid lasts forever - just means it's likely to last long enough for the warranty to run out. Hell, my Volvo doesn't even have an oil
dipstick! Does that mean oil never needs to be checked and maintained?