What I meant with that question is: Who cares? As long as it's cool music I can enjoy listening to (or playing it myself) it's fine with me.
I play in a band called Superfloor. We started out as a cover band doing lots of SRV, Jimi and ZZ Top etc.
We got booked by Blues clubs, we got airplay on Blues shows and people called us a Blues band.
When the band got to the stage where we started writing our own stuff, the direction shifted somewhat towards more rock orientated music. With ingredients of Hard Rock, Blues and Soul. Because you get inspired by what you love.
Nowadays when we do gigs there's always a few people in the audience complaining that "this has nothing to do with Blues".
So what?! Why does it have to be strictly Blues? And -again- what is Blues?
To me it's everything between Robert Johnson and -for example- Gov't Mule.
But I don't care if someone else tells me Gov't Mule is not Blues.