I think you conflate marketing with technical change. There are multiple reasons given above why strict semantic versioning is not used in real-world software,

I think you conflate marketing with technical change. There are multiple reasons given above why strict semantic versioning is not used in real-world software, that is a reductive summary of one of them. Yes, I've read those articles a while back when they were written. In a very real sense, a consumer can never be sure that software keeps running properly if a library changes in any way without extensive checks. Real-world loose semantic versioning is a promise, not a proof, and it works better that way. I don't personally think the current go proposal is terrible or sucks, but I do think it could be improved, and it'll be improved by listening to how people use versions.