Melodic death metal is indeed becoming more and more mainstream... but that's not a bad thing in my opinion. Melody, hooks, and catchiness do not have to be our enemies. They are elements of music that anyone with an open mind should try to appreciate.
Everyone gets something different out of the music they listen to, and that is their right as human beings. If stupid trendy kids at school buy In Flames T-shirts after hearing the first ten seconds of Embody The Invisible and that means something to them, we are in no position to judge them.
We also have to realize that our wishes and an artist's wishes may not be the same. For all of us to covet our precious Soilwork to the point where we try to keep them from gaining exposure when exposure is what they want is extremely selfish. Soilwork's music isn't ours just because we bought a circular piece of plastic and chrome that plays their songs from Fye. The music and the inspirations behind the music, be they wealth, fame, ego, or expression... these all belong solely to the artists. Those artists are free to change and evolve however they choose to, and fans labeling or deserting them just for changing in a way that is generally disliked is incredibly arrogant.
I hope melodic death metal does become popular. The more diverse music becomes, the more diversity there will be in the future... and diversity is a good thing.
I'll admit it though... if I see preps wearing In Flames shirts in a year or so at school, I'll be the first to point it out and crow, "I TOLD YOU SO YOU STUPID SHEEP!"