For standalone software like databases or CLI tools AGPL isn't an issue, if legal departments would object against using such software those companies couldn't run Linux/GNU tools either. For libraries it's a different story of course. The other points are mostly true, I think if open-source is just a marketing strategy to you it's not worth it.
No, Elastic was licensed as Apache 2.0, which is much more liberal than AGPL. Also, they changed the license because a large company basically resold their solution withtout granting them a share of the revenue. OPs point about the (A)GPL was that it would hinder the adoption of OS software by companies.
