I don't think this level of absolutism is justified. I think that it's a stretch to define cloud providers as "users" in the first place:

What is Akka? A distributed messaging platform.

If you want to use Akka to move messages, then the SSPL is just like the AGPL to you. (Even if you're Amazon! No discrimination against trillion-dollar companies!)

If you want to use Akka and Akka's code to learn how messaging work, then the SSPL is just like the AGPL to you.

If you want to use Akka's code as a starting point to author your custom messaging platform, then the SSPL is just like the AGPL to you.

When is it not like the AGPL to you? Only when you don't want to actually use Akka yourself, but you want to charge others a fee to let them use Akka on your server.

In that case, and only in that case, SSPL says "you are not a user of this program and are not entitled to the Four Freedoms". I find myself in agreement with that assessment.

EDIT: I originally mentioned the BSL in this thread, that was a mistake. The BSL (free except for users >$25M) is a non-free license that I consider legitimate and understandable and better than almost any other non-free license, but less than ideal. The SSPL (free except for cloud providers) is the non-free license that I find most acceptable, to the point where I think AGPL projects will make the world a better place by switching to the SSPL.

As established in my earlier comment, your original premise and your entire argument is incorrect. Akka is not a 'messaging platform'. It's a bunch of libraries that you link in to your JVM app. No one (well, no sane person) would try to 'charge others a fee to let them use Akka' on their server because technologically that doesn't make sense. It's akin to charging people a fee for a service to concatenate strings together. Hence as you can see, the SSPL is not an appropriate fit for Akka anyway.