Kickboxing is a 'more complete sport' than boxing, what the hell does this mean?

[ReB]

I've seen in a comparing of these two sports this kind of rubbish spoken about kickboxing. I'd love to see one of these douches step into the boxing ring and show off their 'more complete' skills. I think people seem to forget that Boxing is not supposed to mirror an actual fight, and anybody with that assumption clearly knows nothing about the science of the sport of boxing.

[Zodiac]

You roundhouse kick someone to the thigh. Then their balance is off and pretty much easy win. I boxed, and took martial arts.. Kicks are very powerfull. Especially if u got strong legs like me lol.. I wouldnt wannt get kicked by me.. Its like having 2 arms on each side insted of one lol

[Nick]

It essentially means that people who do kickboxing have a wider range of attacks and defenses at their disposal. Instead of using only fists, kick-boxers can use their feet and legs as well (obviously).
Having two extra limbs that are able to be utilised makes kickboxing more advantageous; not only are you able to inflict stronger strikes upon your opponent (spinning head kick for example is easily more brutal than any punch), but you also have greater reach when using legs to strike.
Take into the account that if you have a kick-boxer who is equally as good with their hands as a boxer, the kick boxer has the advantage because they would easily excel in utilising their lower body, whereas the boxer cannot.