I kind of agree, it would be nice to have a push cart in which the bag stood straight up or faced forward. To the comment above and walking around the bag, in the current state of push carts, you have to walk around the back to the put the club back in the bag anyway. If it faced forward, you could put in directly after hitting, and you would not have to deal with the arm / handle of the cart being in the way.
If you remember back to when they were all pull carts, the bag also faced toward the handle, suppose most of this is probably due to the balancing of the weight of the clubs and bag while keeping the total length of the cart as short as possible.