Diane Greene at Google wasn't doing a bad job at all. As a matter of fact, she was leading the massive business, Google Cloud, and taking it in the right direction. But being second fiddle to Google Ad sales and then having to navigate around something new from Google every month is no easy task. The Google Graveyard is full of other so called failures, some of which were good ideas but not successful.
However, it was made harder by the internal competition between divisions and personal agendas of each divisional CEO. So when Google became Alphabet, and each company had to start to account for their usage of Google services and infrastructure vs. it all coming out of a shared pool, internecine rivalry and priorities had to take hold.
Google Cloud is every bit as good, or better than Azure or AWS. However, the difference is that at both Microsoft and Amazon their clouds are a priority, and a core part of their marketing and sales efforts. They don't fight against their cloud sales effort, they embrace it and make it something that everyone is aware of and actively supporting. For both companies, the route to the Enterprise starts now with the cloud as evidenced by MSFT's push of Office365 before they mounted a big drive for channel partners to sell Azure.
Google has a built-in Cloud customer base. It's every user of anything Google, and that starts with GSuite, YouTube and YouTubeTV. Those categories present a variety of sales and marketing opportunities to sell Cloud and cross-sell other Google services, and that includes using Ads as a loss leader. So while reports are that some of that was starting to happen, it couldn't happen soon enough.
At the start of the year, I presented concepts like that to the rep selling Google Next to me for a client. I proposed a series of cross-collateralized marketing promotion ideas that would have been of value to Google and my client. So while viewed by the rep as what was needed to make the event great, Google's Cloud team came back with basically a vanilla proposal, not for lack of interest but due to a lack of internal capacity to make things happen.
That's what's likely did in Diane Greene. Not what she and her team wanted to do, but what the company prevents from happening due to the way the business is structured, and how the corporaticians can win out over the bold and the brave.