People crave sweets — cakes, candies, cookies and sodas galore — but cats are generally unimpressed. A cat's tastebuds are incapable of detecting, appreciating or triggering a craving for foods that we recognize as "sweet."
As "obligate carnivores" (those that need meat protein to survive), cats simply don't need sweets. It's unclear whether the ancestors of cats had the ability to detect sweetness and lost it, or whether cats never developed a "sweet tooth," since they didn't need it.
People eat a much more varied diet, and our taste buds reflect that — we have nearly 10,000 on our tongues. No such variety for cats: They're happy to stick with small prey animals and need fewer than 500 taste buds to figure what's on the menu and what isn't. No doubt their limited abilities in this regard factor in the well-known finickiness of cats. So, feel free to lavish your cat with love. Just save the sweets for yourself.