4 pin molex is used rarely nowadays, but some fans come with it and some cases with fan controllers are molex only (Fractal Design R4). I also had USB 3.0 controller that needed MOLEX to work. Hell the most shocking thing is that I bought SATA to IDE adapter that needs floppy power connector to work. In the past cold cathodes, HDDs, ODDs, various other stuff are MOLEX only. MOLEX certainly has its uses, just that plug design is so awful.
BTW some old board, which had EPS connector, but 4 pin one actually managed to put it in different places other than that damned corner. Here are some examples:
You see, they could even put it where 24pin is now, I see no reason for EPS to bee in that cursed place. It's really not a rocket science to switch RAM position and rotate CPU socket. Really simple stuff, but it seems that nobody cares.