There is nothing wrong with slam.Nothing new there, just a new term.
Wether, it is a poetry night, a painting night, a combination of both or a music jam session, all the same. If you create something you want feedback.
It is a social thing for artists. It is worth what it is worth, it is entertaining.I see it like a comedy night. Some very witty stuff comes out of it, a lot of shit as well but it is mainly a social gathering, a challenge for artists, like rap, a flame thrower, a go at communicating with spectators, a thrill.
I think it is great. Is it art? sure. It is not the first time that things like that take place. In the seventies, it was part of bringing art to the streets for the common people and out of museums, out of libraries. Painting the sidewalks, a happening! Even in the sixties, poetry was being read out loud in cafés , bars, on street corners. What is is worth? who cares, it is about expression, whether you are doing it in a studio, a room, or on stage. Whatever gets you through the night is alright.You do not have to bleed yourself in public, it is all about being alive and sharing it.