https://opensource.google/docs/using/agpl-policy/
Now, one can read into why exactly this may be, though I have a strong feeling it is simply due to the fact that enforcing correct use of the license is harder than usual. Even if you use it alongside only compatible licenses, like GPLv3, it presumably would make the entire distribution subject to AGPLv3 restrictions. GPLv3 virility is a little easier to deal with, and of interesting note the Bazel build system contains some awareness of licenses.
https://docs.bazel.build/versions/0.24.0/be/functions.html#l...
On the other hand, one might view this as a benefit. So, I guess it depends on who you ask, really. It's not clear that big corporations would necessarily have an easier time with SSPL or TSL either.
Note: IANAL, please do not take my understanding of how these software licenses work as fact :)