If SolidCoin had come first then we wouldn't have had this decision at all, it wouldn't have gotten the kind of mindshare that BitCoin got at all.  It may have gotten popular for a little while, but probably would have quickly gotten in trouble and faded.  In many ways it's riding the coattails of BitCoin, trying to say "we're like BitCoin, only better!".

And if you haven't heard of SolidCoin, about half the threads in alt coin have been talking about it, I think it's been the favored piniata in these forums.  A couple "run away! run away!" threads have appeared in this forum as well.