Since when did the freedom of true choice disappear? Why do we have to judge the Darkness on their fans, or by their predecessors? Yes, true, some older fans may be put off by the youth following, and likewise some of the younger fans may be put off by the older following. However, a true rock fan cannot truly dismiss a band because of their following. Musically, the Darkness may not be the best musicians ever, or may not have come out with the best songs ever, but they're still pretty damn good. They're one of the best things to come out of England at the moment. (For more great bands coming out of England at the moment, look at the Liverpool revolution, for just one example.)
The Darkness are fun, and are not one of the bands following out of the arses of pop-punk. They have ignored the years of dance and pop, and stood looking into the past, present, and future, of classic rock and metal. If this band cannot liven up the rock scene at the moment, then no-one can!
In summary, the Darkness may indeed be extremely big in the popular music world, but that doesn't mean the rock scene should ignore them. As various people have said, it's a matter of opinion, but in my own opinion, this album is brilliant.