I don't like this.

He's achieved meme fame.  
 

I'm not ashamed to say I watched the whole video

just in case, this is an honest question

just provided a very good example

I'm sorry if you got trust issues now :c

The honest answer is that it's allowed because nobody thought to disallow it.  If they'd thought about it, I give it pretty good odds that they'd have disallowed it, because it is a very weird thing to intentionally allow.  

Shortened links can redirect to malicious places without us knowing (we'd have to click the link).

Doing this still allows us mods/admins to hover over links and quickly hide anything that's malicious.

Plus shortened links can link you to redirects that track your activity.

ah, as I expected

thanks

Rick Astley , 90s King !!