It's not only unsafe but possibly criminally negligent to operate this as is shown on that page.

Casually tossing around phrases like "criminally negligent" spoils all the fun of hacking. Seriously. You are strongly overreacting. Haven't you ever been to a laser show? All that's shown on the linked Hackaday article is a DIY laser projector projecting some cool designs. I don't recall seeing any pictures of people pointing lasers at other peoples' eyes.

Further, it looks like this was all done inside of a research lab by someone who knows what they are doing.