Why do guys go for girls?
Why do guys tend to go for certain types of girls?
As for them ALWAYS going for SHORT girls. That's simply not true.
It may be true in your anecdotal experience, but do you have a large enough sample size for it to be statistically significant?
It also depends on your perspective. If you're a 6' 4" tall female you may consider any girl under 6' as "short". In which case the answer to your question would be pretty self evident.