heavy metal & blues question ?

Metal really developed from the 60s heavy blues scene. Hendrix, who's guitar playing is really where most people consider the origins of metal to begin, was a blues guitarist. Most metal riffs are just rapid variations on blues ones anyway. I wouldn't really say that metal 'incorporates' blues, but that metal itself stems from blues, so naturally has some blues-ey elements to it.

Also, blues is awesome. Why would you not want to incorporate it anyway?

Well heavy metal and blues rock are different. Blues rock is more Joe Bonamassa, and the blues-base rock/metal guitarist would be guys like Zakk Wylde and Jerry Cantrell from Alice in Chains. Everything ties back to the blues. Play what sounds good, so why not?

Well, why not? Honestly Blues affected heavy metal in it's early development, and Blues licks and beats are as heavy as can be, just not distorted like heavy metal. Probably getting back to the roots of the music is good. Which is why many artists have simple Blues-y beats.

Heavy metal evolved out of blues.

Listen to Black Sabbath, Led Zeppelin, Deep Purple, Jimi Hendrix, and Cream.

Because all forms of Rock music stems from Blues. As does Country, Bluegrass and Gospel.

Heavy Metal musicians are staying true to thier roots.

I think a lot of it has to do with them being mostly self-taught players. Like those guys, I use a bluesy style because it's cool and was relatively easy for me to teach myself.

It's already in there they just play it differently Faster & multiple hammer ons.