Kanye West -- I'm the Simon Cowell of the Streets ... Gives Rapper Shot at Fame

Kanye West was verbally assaulted on the streets of NYC ... and he liked it ... giving a total stranger several minutes to show off his rapping skills on camera.

Kanye and Kim Kardashian were walking to their home in SoHo when a guy -- who's either really brave or really dumb -- ran up behind Kanye and boldly said, "I been working on my s***, trying to get better at it."

This is where old Kanye shoots the guy down and crushes his dreams -- but the new KINDER Yeezy instead replied, "How's it sound now?""

And then ... the guy spits his rhyme for more than a minute straight! Kanye even waited for the guy to finish before walking into his building!!