Tweaks like Five Icon Switcher have been out ever since Apple released iOS 4, but apparently there's still a demand, or at least a perceived demand for tweaks of this sort.
There are many other tweaks that allow you to do something similar, cramming more app icons into a space that was meant to be limited.
Although 6Switcher -- a tweak that stuffs six app icons into your multitasking bar, might add more function to your device -- what it takes away can't be justified in my opinion.
Honestly, I'd rather deal with a few extra swipes than ruin my iPhone's aesthetic appeal, wouldn't you?