There are several questions concerns raised in your post. I’ll try to address them one by one. I’m sure other people may have similar questions/concerns. The following is my point of view based on events that led to where we are today.
Q: Why are we using a dot extention (.safenet) instead of a new protocol like (SAFE:)?
A: We initially tried to use (SAFE:) to replace (HTTP:) but this required a browser plugin for each browser, which means download and installation, and then support from browser updates like (firefox, chrome, and others). It came down to what works and ease-of-use. MaidSafe transitioned from (SAFE:) to (.safenet) which made the browser setup VERY easy and less work for the devs. We don’t need a plugin anymore… just copy/past the .pac address into your browser settings and you’re good to go.
Q: Why do Public ID’s behave like DNS on SAFE websites?
A: Accurate navigation is the main reason. If we tell people go to (dyamanaka.safenet), everyone must navigate to the same website. Some would argue this isn’t a problem using a decentralized listing service… see thread V - No DNS. We have 6 threads discussing solutions to website navigation, squatting, transferring, and ownership. You can review and comment these threads in more detail. As a consumer specialist, it comes down to a better user experience. While people like familiar, they’re also willing to upgrade if it makes life easier.
RFC - Decentralised Naming System
RFC - Decentralised Naming System II - continuous auction (by Seneca)
RFC - Decentralised Naming System III - prevent domain transfer (dirvine)
RFC - Decentralised Naming System IV - inhibiting domain squatting (happybeing)
RFC - Decentralised Naming System V - No DNS
The Petname System
Q: That is a valid concern. Said another way… who gets exclusive “use” over commonly used names?
A1: These Public ID’s must be (unique) in order to function correctly. Imagine dialing the exact same number and randomly calling up 1000 different people. Someone suggested adding a random 3 letter extention (david - XBG), allowing more people to use a common name. We may need a listing service to find and sort all the different variations… similar to a phone book directory. But I think people already resolved this issue… see A2 below.
A2: (Unique) conflicts with (Common Names). I’ve seen this in popular MMO games and social networks. To my surprise, users come up with different variations of a common name, and somehow life goes on… however see A3 below.
A3: We are talking about a global internet. The population could grow into a billion users! If that ever happens, I’d be super happy we impacted the world to that degree. Perhaps, we will have a better solution in the future. But as @bluebird mentioned, people prefer names that are easy to remember. Unfortunately, this is a limitation of human memory.