Hard to find? Wandering new chunks I have no shortage of them. Given how they outperform a minecart system for almost everything ("automated transport between two fixed locations without any attention" is the only thing left for minecarts, and that has a cost that increases linearly with distance), it's more like "why bother with minecarts"?
My solution: Make Minecarts faster, make Pigs faster and make Horses require a ridiculous amount of food (speeds and hunger configurable)