We see this again and again. The cynic in me sees Stadia as yet another internal promotion scheme, masquerading as a product.
I doubt this will ever change. The internal momentum of the company culture will make it so. What does it mean for investors? Google has enough money they can just buy their way into markets indefinitely. It will probably keep them going, but I don't expect huge growth. I'd probably be putting my money into other stocks if I had to choose. I honestly don't think people would miss Google much if it was gone.
I can recommend reading In The Plex. Quite literally the founders wanted to invert the usual model and put engineers first. There were some anecdotes from those in roles like marketing and so on that they felt like second class citizens.