I'm not sure if I'm the only one but every time I pick up a sata 3 cable its got an angled end. Just picked up a kingston SSD for steam games and trying to install it on the 3.5 - 2x2.5 drive converter got with my case. Now I got a sata 3 expander card because my mobo only has two ports. 1 now because I had to put the stupid angled bit in the board on the top port blocking the bottom. so I could use the flat end on my boot SSD. &*))U*!! why do they do this to us??
Why do angled sata 3 connectors exist?
I personally don't like them either, but they're there for instances where the either the sata ports or the hard drives are close to the case or another component. It keeps you from having to bend a regular one and putting stress on the port. For example the Sata ports in my ASUS mobo are facing towards the front of my case(90 degrees from the mobo) and if my case had a cage or something right next to those ports then I'd use the right angle connector.
Usually it's only on one end of the sata cable, so you can use the straight connector on the mobo and the 90 on the hard drive.