> So the license is closest to GPL than anything.
That's not close to GPL at all. GPL is "if you use our software and modify it and distribute the modifications, you must do it as open source". AGPL is "same as GPL only you must also publish modifications if you're just using it". SSPL is "if you touch our software you must open-source your whole data center". The message here is clearly "don't ever touch our software unless you're already 100% open source shop". GPL never went this far, and for a good reason - nobody in commerce would touch GPLed software with a ten-foot pole if that was the case. People are wary of GPL, but SSPL is taking it to insane length, clearly construed to disable, not enable, it's use.