If you told that IPFS is a protocol, why do not use “ipfs://” for canonical links?
The browser extension “IPFS Companion” is using “/ipfs/” for canonical links, why not “ipfs://”?
Typing ipfs:// in the browser would be more beautiful and simple than the ugly and proprietary https://ipfs.io/ipfs/
The browser could find directly the file behind “ipfs://” in the network, instead of going through the “ipfs.io” server. This would be truly decentralized and easy to share.
An ipfs link is easier to share and less destructible than a ordinary, ugly, and centralized http link.
The only problem with the ipfs:// link is that you would have to install a browser extension (or a new browser itself, who knows?), but we can hope that common browsers will include the ipfs:// protocol directly in their code in a near future.
See this github thread for an extensive discussion. The link is to a comment that attempts to summarize the thread.
TL;DR: ipfs:// in particular is reportedly wrong according to W3C rules for non-authority based protocols, but protocol labs’ tools will redirect ipfs://.
Support for Custom Protocols in WebExtension is an ongoing effort and is tracked in ipfs-companion/#164 (includes search hijacking and other dark arts)
TL;DR
browser extension enables users to copy either:
Canonical, future-proof NURI (Nestable URI a.k.a. path addressing), as it can be used in both browser (by prefixing it with dweb:) and command-line tools (as-is)
URL to resource at public gateway (that can be shared with people without IPFS extension/daemon)
ipfs:// support and usability are highly limited (that is why it is not “canonical”), for more context:
partial native support in Brave (progress tracked here)
no native support in Firefox and Chrome, only redirect to gateway URL (ipfs-companion/#164)
The simple answer is that the colon makes it NOT compatible with Unix filesystems while the way it is structured now with /ipfs/ makes it so that it is compatible with unix filesystem which opens a whole new door.
Juan Benet explained this in one of his talks but I can’t remember which one.