Right, 2014. Although I’m not sure anything has improved on his main complaints. There is no possibility of compatibility between binaries for the end user which means the experience will rarely be download and run. The distorts will always be incompatible, the package managers don’t care about you, and the core system components will break things in the name of progress (for them, hope you can come along!).
Linus Torvalds uses AppImage for his diving app subsurface. He is on the record saying he endorses it, and you can find a quote by him on the AppImage website. I don’t think he would have anything good to say about snap. I don’t think he has said anything about flatpak