@probonopd this is a wiki so I suppose anyone can edit it but thought it would be wise to get consensus before changing it…! The description seems harsh though.
‘Now claimed by Canonical to be cross-distro, but appears to be mainly a frontend to a central App Store with Canonical as the gatekeeper’ - this part is correct. The claim that it’s cross-distro is based on the fact that it runs on many distros. The nature of the centralised app store is not planned to be changed anytime soon because there are higher priorities.
‘ubuntu-core as a required runtime’ - that’s changing.
‘Snappy appears to be about ensuring Canonical control first and foremost.’ - ouch!
‘A Contributor License Agreement (CLA) needs to be signed to contribute.’ - I know this issue is controversial, but the CLA is based on this template designed for FOSS projects to use… But obviously what the wiki states is a fact.
‘While Canonical claims everyone can operate a store, each device is allowed to have one store only.’ - Yeah that’s not the official line anymore (even though possibly still workable in theory) 
The official line is that there’s one store, plans to change that are not prioritized. I think you can have ‘branded stores’ which are a subset of the snappy store but I’m not sure about the detail and, as far as I know, they’re still effectively part of the main snappy store.
‘If I understand it correctly, everything runs on certificates that Canonical centrally controls and plans to monetize.’ - the writer does not apparently understand it correctly! I’m not aware that Canonical plans to monetize this.
‘Also, everything is supposed to run “confined” by the system and apparently if an application needs extra rights, this becomes a subject of commercial discussion with Canonical.’ - errr, nope. You just add plugs.
‘In contrast, AppImage is designed as a de-central system which gives all the power to application authors and end users, with no central intermediaries in between.’ - Yeah that’s true!
