Their worry is that competition will be started by the people they've not hired and kept on the bench. I'd imagine a large amount of their top-level hiring is driven by taking minds off of the market, more than optimising their output.
So make it not bullshit. It may feel bullshit because it's bullshit or because the exec deciding your project had bad info and you have good info, or you have bad info and not getting the context...
go out there, talk to people, find if it's really bullshit, and if it is, change it. there are so many interesting problems to fix that nobody should have time to do bullshit jobs
Some people are brilliant but just want to be financially comfortable enough to do the things they actually want to do. Ask some CS majors why they are trying to get into the field and a huge swath with frankly say it's because they can bust ass now and get six figures at 22 years old and coast the rest of their lives. Not exactly the reality, but that's what freshman CS majors are thinking about when they hand their resume to the google rep during the career fair.
It has worked, perhaps not for long, but outweighted sums of cash to play with a nice side project or work on an actual "at scale" thing whilst you vest some shares probably appeals to a lot more smart people than we might imagine.
Salaries are also deductible, so they get the talent in their pool, off the market, adding a small % of value, whilst also being able to offset taxes on record profits.
Real != profitable. Google can offer academic style oppurtunities at industry style salaries.
Eg. Fuchsia OS might have been started because Google saw a bussines oppurtunity in writing an open source capabilities OS. Or, it might have been started to keep smart OS engineers from leaving the company.
Not just Linux, but ChromeOS is based on Gentoo Linux (originally Ubuntu); which is to say, much of the userspace stack was pre-exsting as well. The core of the operating system is the Chrome web browser, which was also a pre-exsting project, which a relatively clear business interest to Google (influence over the web platform).
Android has a bit of a better claim, as more of the userspace stack was written for it. It also wasn't started by Google (although they bought Android Inc. years before it was released publicly).
Their worry is that competition will be started by the people they've not hired and kept on the bench. I'd imagine a large amount of their top-level hiring is driven by taking minds off of the market, more than optimising their output.