@keithpp @CobaltVelvet I don't think it's any more fatal than the fact there are lots of John Smiths in one town or another. At least here there is only one per town (instance). People deal with that fine in real life, why not online. This also remove the feeling we need to have a globally unique handle for everyone to know us. That's not feasible with 7 billion people. When you see post from the truncated name you can then click their id to see the instance. It's a natural thing to me.
@keithpp @rateldajer @CobaltVelvet Said differently, it'd be like saying "My username is keithpp" without saying where. You'd say "My username is keithpp on Twitter" or "My email address is user@domain.com."