"...the production style also added authenticity of the music, emphasizing it's immediate, raw, street level sound"
Follow that up with a quote from Benjamin's article:
"it's presence in time and space"
Not in the sense that the bands were covering anything, but to take the quote literally, as in what the music stood for in each era, it had it's presence in that time and space where it was.
Another important quote from the Baily, and Collyer article
"[music] has potent emotional connotations and can be used to assert and negotiate identity in a particular manner"
The influence of these bands is unmeasurable, countless acts have stated them as influence sound wise.
To go beyond sound with the internet DIY morals are even more in use today with lots of bands needing to do everything for themselves.