Correct me if I'm wrong:

Most links are sent via text (email, messaging, social networks) where they're automatically turned into hyperlinks. Length isn't an issue here.

When they are spoken, vowels help a lot. It's not fun to spell out D-K-L-O-DOT-CO, no not COM, CO.

In the end though, I don't think it matters that much either way, just bikeshedding.