Legit Reviews

How many vendor machines (dell, hp, etc) have YOU opened up that were just a mess of cables? Granted, they make attempts to enable air-flow, but its still piddly compared to an optimized rounded-cable, multi-fan, water-cooled machine. Adding fans and uber-cool heat dissipation solutions is certainly a major cost hit. But rounded cables? C'mon! I can't comprehend how the big dogs aren't doing that.

rounded cables are just a little more expensive to make and most major vendors consider the only benefit of rounded cables to be cosmetic... meaning it just looks better.

Air flow is not increased enough for vendors to justify the increased cost of rounded cables. For vendors, if they are not having stability problems caused by heat, then they won't change anything to improve air flow... especially if the case doesn't have a window.

adding to what Justin said....Dell, Gateway, etc don't overclock or tweak their machines. If you are happy with a stock machine, you don't need to have rounded cables.
that being said, most of those crap machines are budget for a reason, they are a serious mess inside.