They do allow you to profit off the software though, by using it to host the service for yourself (even as a company), you just can’t offer hosting as a service to compete with them. Obviously this doesn’t offer as much freedom as just a straight MIT or Apache license, but I feel like it still qualifies as open-source; they are only really adding one restriction, and it could even be considered less restrictive than something like GPL (no requirement to open source derived software). I think this license makes a good compromise of being as open as they possibly can without AWS/GCP/Azure eating all of their business without doing any real engineering work.

One difference (so far as I know, I’m not an expert on either situation) is that MongoDB requires copyright assignment for contributions seemingly because the license is so restrictive they can’t offer their own service under its terms (without open-sourcing all the software they use to host it). So far as I know Sentry does not require this (although the restriction against running a competing service does not affect them since they are the service, so I’m not sure this argument really holds up that well). Also the fact that that one encumbrance is released after two years helps their case a lot in my eyes.