New players do not have carts and the tent only holds one horse (and only lasts a week). Old players may have a cart, but would sometimes like to have a third horse just for riding around camp. If an old player decides to set up an out post or go on an adventure, it can be difficult to have a "camp" and keep the three horses needed. These reasons are why it should be added for other people. Personally, I am just starting a settlement (with nothing but my starter items) and have not found iron yet. I found two decent horses wandering about and can only keep one horse tied up without taming. I already lost a tamed horse because of a troll sneaking into my camp. I need iron to build a fence to keep the horses. It would be nice to be able to tie them up to a hitching post. A post can hold up to four horses, but would not be "safe" as any player can walk by and take them. Please consider this as a new addition.