The Free Software Foundation exists to protect the former at the expense of the latter.
Corporations are sometimes users, and individual people often benefit from denying access to the source code of software that is used to provide a service.
Providing a service is fundamentally different from providing software.
To the detriment of the users of that service--which are the people that the FSF aims to protect.
My customers, for example, to whom I provide service, are not infringed upon in any way because I use private forks of GPL software in the provision of my services.
The issue is that I—and, more importantly, your customers—must simply take your word for it, since we're unable to confirm or deny it for ourselves if you don't make the source available.
When dealing with large corporations, taking such statements at face value is pretty foolish.
You might not want to admit to yourself that your business model is based on infringing on the freedoms of these users of GPL software, but that's exactly what it is.
The AGPL doesn't require you to provide the source for software that you're using to provide a service - only the source for software where the software is the service. A bug in software I use is equally annoying when I'm using that software over a network connection as it is when I'm using it on my local machine.
It seems to me that, to defend users against corporations, the FSF as a side effect is attempting to take a whole lot of freedom away from developers who share the ideals of the FSF.
(That is, any developers who publish under MIT / BSD like licenses)
This was never an issue until Google was pinched on it five or six years ago and started a massive campaign to get the OSS movement to disfavor the AGPL. Google uses tons of GPL software that they don't pay for (Linux, Java, etc.) but once it became exterior-facing and the license applied to their software, then rather than pay to license the software, the world's fifth most valuable company decided they'd rather stiff the developers by a campaign to convince other companies of what you just posted.
The free in free software is often cited as being "free as in freedom", but it's important to remember that it's also and simultaneously "free as in beer".
Google, along with everyone else, uses tons of GPL software that they don't pay for - because the point of free software is that you're free to use it. They're not "stiff[ing] the developers" as you claim, because the software is available for all to use for free.
You can't have it both ways: either you're free to use the software for any purpose, or by using the software you owe somebody something. Pick one. I choose the former.
The only reason Google opposes the AGPL is financial. Read their explanations. So, while you're right that Google is not 'stiffing' the developers whose software they're using, by their campaign against the one license that can be used by developers to make money, they are making the OSS world weaker--especially for programmers from developing countries who don't have the luxury of large blocks of time to write software on the side unless they can benefit from a license like the AGPL.
You also wrote: <<Google uses tons of GPL software that they don't pay for (Linux, Java, etc.)>> While that statement may be true on the surface, it belies the fact that Google is either a major, direct contributor to the Linux kernel (and many of its parts). Or: Google is a major sponsor of open source orgs to pay for developers to work on open source projects -- like the Linux kernel.
Also: Are you aware that the Oracle version of Java requires companies to pay license costs when used in a production settings? I cannot say if Google uses a non-Oracle release. But if they do (sometimes) use the Oracle release, I am sure they pay licensing costs. Before you make a claim like that, you should share a source -- one way or the other. One reason why some companies choose to pay the license for Java (instead of using a non-Oracle pure open source release): They want the support when there is a security issue. Example: If you find a bug in the JVM and you are a major customer, then it will be much easier to get support directly from Oracle to release a fix.