[jsmthrowaway]

Except, as you point out, .example and .test exist (and should have been used for this). What's the technical justification for the third?

Remember when APNIC got 1/8 from IANA and had to go test what would happen if they announced 1.2.3.4 to the Internet? Just because something has been done historically doesn't mean we need to ban it entirely from the future.

[koliber]

There is no technical justification. There is a strong culture and habit of using .dev as the development TLD. It has not been codified and accepted formally.

Developers are humans. Technical justification is one of the things that should be considered when making decisions. There are many others.

Developers have not been widely using .example and .test as the spec recommends. They have been using .dev. It makes sense for it to be added as a reserved testing TLD. No one can force Google to do it. We can just petition them and hope that they do the right thing.

There is a lot of goodwill that Google can gain by allowing free use of `.dev`. Even more if they propose a spec to add it to the reserved domains. I would imagine it would be at least $185,000 worth of goodwill.