Not true, precisely.
Both rely on a marketing mystique, certainly, but Tiffany spends a lot more on mass-market advertising than does Hermès. And the Hermès mystique owes a lot to the hand-crafted nature of the products. Hand-rolled edges on scarves. Hand-stitching and shaping on the leather goods.
For someone like me, who is very interested in the small-craftsman *movement,* this is very important. I buy local produce, dairy and meat, and try to buy local and handmade crafts and gifts when I can. Handcrafting of anything is increasingly a lost art and I can understand the cost when you consider the care and man-hours that go into the making of the bags.
And believe me, this is not coming from someone who can afford Hermes leather goods. I have a small (small!) fund I hope to apply to an Hermès bag (one!) someday. But even being a fan from afar, as it were, my perception is that an Hermès bag is a one-of-a-kind original with the stamp of a craftsman on it, rather than a diamond among similar diamonds.
As I have said before, if the Tiffany brand works for you, by all means go for it! It's a wonderful brand, with some lovely jewlery. IMO, however, this particular question is an apples-to-oranges comparison. The question wasn't, "which gorgeous ring should I pick from Tiffany?" or "should I get a diamond or a handbag?" It was Tiffany vs. Hermès, and for some of us, the monetary and aesthetic values of the Hermès bag are greater.