I hate to point this out, but that's a very American viewpoint. First of all, Gardnerian and Alexandrian Wicca (two strains of Wicca which are predominantly English, and were the original forms of that faith before the New Age community in America borrowed it from the handful of Dianic and eclectic practitioners) use the so-called "upside down pentagram" as a symbol of second degree elevation. First degree witches wear a triangle, and third degree witches wear the point of the star up because that symbolizes mind over matter, and one coven leader over a hive of covens. Whereas individual high priests and priestesses (those who have attained the second degree of initiation) must focus on the practical matters of running their own coven, and put their coven first (or something like that; for a better explanation, read A Witches Bible Compleat by the Farrars) so the "matter" part of the pentagram is at the top.
Secondly, star-shaped sigils with five, six, seven, eight, or nine points hace been used for centuries in Hermetic and other occult work for centuries, and various sigils can be seen in various degrees of right-side-upness. Think about it: if you are in a circle, a circle is round; how can there be a right or wrong side when a circle has no sides?
Satanists use the two-points-up pentagram because (among other things_ it is an abstract representation of the Baphomet, the goat of wisdom. The Baphomet has been around longer than the silly little cultists who confuse it with a "Devil," an "apocalyptic Beast/antichrist," etc. It too is just another occult symbol, and it stands for wisdom (goats are smart animals, for one thing; a hell of a lot smarter than sheep. Pigs are smart too, but now I'm getting sidetracked.) The Baphomet was rumoured to be venerated by the Templars. Nobody knows what it was. The Templars were accused of diabolism and Muslim sympathy (pretty much the same thing in the Middle Ages) and somehow the Baphomet became confused with the Beast. But it's been around for a long time, longer than the cultists, if the Templars had it.
What makes a symbol "negative" or "positive," in my very unhumble opinion, is the will of the person using it. Even the reversed swastika only stood for what - death? the hunt? and what is wrong with either? Death is a part of life, and without it we would overpopulate our planet and be miserable. Hunting is also a part of life, although we like to think that herding and factory farming are less atavistic and don't really kill real living creatures; the meat that we see in the supermarket was created by conjuration only...Really, what makes the swastika so terrible (in either form) in these times is its association with the Nazi party. Which was, assuredly, quite evil. As evil as the society which let it take control. Well, maybe not an evil society, but certainly an ill one.
We are vampires. Even those of us who are as hopelessly sensible as possible and try to avoid mystifying ourselves ought to be honest with ourselves - we have the hunting instinct, and we have that eros/thanatos thing that makes us have some connection with death. The little death of endings, or dissolution of ego in the joy of feeding, if not necessarily always the big death. The little death is a shadow of what could be. We shouldn't run away from that...That isn't evil. That's just life. Who are we to impose rules and morals on life itself? I think life has been around a little longer than we have.