Not That Tall

I'm 1.81 m (5'11) and I don't think I'm very tall, but people always say that I'm very tall and that is regarded as a very good thing. Really, I don't know why, it is seen as a good thing: the taller a person is, the more energy he/she will need to keep the body working, therefore more resources will be needed. And being tall doesn't offer any good advantages I can think of.
Probably people think I'm tall because in my country (Portugal) the average hight for a man is shorter than mine.