I'm 5 foot tall so I'm pretty petite and guys are always commenting on it. Girls never really have much to say about my height but when talking to guys they will always comment on how small I am or give me some good natured teasing. Its not mean, I know they are just poking fun and they always say its cute. My other friends that are small get told the same thing but guys have never commented on my taller friends' heights. So why do guys tease only short girls? Why not tease tall girls also?
Teasing is flirting. The explination behind this was quite recently shown in a very good study relating showing embarassment having a correlation to your likeability as a person; guys tease you and like you more for it.
As for why tall girls aren't teased as much, well in a womans case being taller than normal isn't quite as good as being shorter than normal so I suppose its not as 'friendly' to draw attention to it.
Because guys like to tease ALL girls not just short girls.
Short girls are adorable and it's something they can easily jump on as far as teasing goes, probably with little risk of offending you. Whereas taller women might be more sensitive about their height, just as shorter men can be sensitive about theirs.