I agree with you that it is not an evolutionary trait. But you might note that since it is a survival advantage, it does loosely fit the definition of "natural selection" - a prime argument used in evolutionary theses.
How is it a survival advantage to be tall? A minimum height probably is but I fail to see the advantage of being 6'6" vs. 5'6". A larger person requires more food to maintain and as tool users we humans do pretty well even if we are small. Small populations exist and thrive around the globe. Tall ones do too. It's setting-dependent as to whether or not it's an advantage.
Oh, and in case you're wondering, I'm 6'1" and 190lbs so my position is not partisan ;-)