I don't think you emphasized enough the "far less likely to adopt their next big idea" bit. It's massive. Developers used to simply assume whatever Google puts out is going to be huge, and the sooner they get onto it, the better off they'll be. Now, anything that Google puts out, it's far more sensible to take a "wait and see if other people use it" approach. If enough people do that, no one uses it!

I think Google are generally smart enough to factor this type of thing into their decision-making around "should we shut down X" but their approach to shutting things down does make me wonder how they value it.